Method and apparatus for state/mode transitioning

ABSTRACT

A user equipment implements a method of processing indication messages, such as SCRI (signalling connection release indication) messages. The user equipment (UE) maintains a count of how many indication messages with a cause set have been sent by the UE while in at least one radio resource control (RRC) state. Various conditions are provided for resetting the count. These include receiving packet switched (PS) data by the UE and transmitting packet switched (PS) data.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of and claims the benefit of U.S.patent application No. 12/953,049, filed Nov. 23, 2010, and U.S.Provisional Patent Application No. 61/263,822 filed on Nov. 23, 2009,which are hereby incorporated by reference in their entirety

FIELD OF THE DISCLOSURE

The present disclosure relates to radio resource control between UserEquipment (UE) or other wireless or mobile device and a wirelessnetwork, and in particular to transitioning between states and modes ofoperation in a wireless network such as for example, a Universal MobileTelecommunication System (UMTS) network.

BACKGROUND

A Universal Mobile Telecommunication System (UMTS) is a broadband,packet based system for the transmission of text, digitized voice, videoand multi-media. It is a highly subscribed to standard for thirdgeneration and is generally based on Wideband Coded Division MultipleAccess (W-CDMA).

In a UMTS network, a Radio Resource Control (RRC) part of the protocolstack is responsible for the assignment, configuration and release ofradio resources between the UE and the UTRAN. This RRC protocol isdescribed in detail in the 3GPP TS 25.331 specifications. Two basicmodes that the UE can be in are defined as “idle mode” and “UTRA RRCconnected mode” (or simply “connected mode”, as used herein). UTRAstands for UMTS Terrestrial Radio Access. In idle mode, the UE or othermobile device is required to request a RRC connection whenever it wantsto send any user data or in response to a page whenever the UTRAN or theServing General Packet Radio Service (GPRS) Support Node (SGSN) pages itto receive data from an external data network such as a push server.Idle and Connected mode behaviors are described in detail in the ThirdGeneration Partnership Project (3GPP) specifications TS 25.304 and TS25.331.

When in a UTRA RRC connected mode, the device can be in one of fourstates. These are:

-   CELL_DCH: A dedicated channel is allocated to the UE in uplink and    downlink in this state to exchange data. The UE must perform actions    as outlined in 3GPP 25.331.-   CELL_FACH: no dedicated channel is allocated to the user equipment    in this state. Instead, common channels are used to exchange a small    amount of bursty data. The UE must perform actions as outlined in    3GPP 25.331 which includes the cell selection process as defined in    3GPP TS 25.304.-   CELL_PCH: the UE uses Discontinuous Reception (DRX) to monitor    broadcast messages and pages via a Paging Indicator Channel (PICH).    No uplink activity is possible. The UE must perform actions as    outlined in 3GPP 25.331 which includes the cell selection process as    defined in 3GPP TS 25.304. The UE must perform the CELL UPDATE    procedure after cell reselection.-   URA_PCH: the UE uses Discontinuous Reception (DRX) to monitor    broadcast messages and pages via a Paging Indicator Channel (PICH).    No uplink activity is possible. The UE must perform actions as    outlined in 3GPP 25.331 including the cell selection process as    defined in 3GPP TS 25.304. This state is similar to CELL_PCH, except    that URA UPDATE procedure is only triggered via UTRAN Registration    Area (URA) reselection.

The transition from an idle mode to the connected mode and vise-versa iscontrolled by the UTRAN. When an idle mode UE requests an RRCconnection, the network decides whether to move the UE to the CELL_DCHor CELL_FACH state. When the UE is in an RRC connected mode, again it isthe network that decides when to release the RRC connection. The networkmay also move the UE from one RRC state to another prior to releasingthe connection or in some cases instead of releasing the connection. Thestate transitions are typically triggered by data activity or inactivitybetween the UE and network. Since the network may not know when the UEhas completed the data exchange for a given application, it typicallykeeps the RRC connection for some time in anticipation of more datato/from the UE. This is typically done to reduce the latency of callset-up and subsequent radio resource setup. The RRC connection releasemessage can only be sent by the UTRAN. This message releases the signallink connection and all radio resources between the UE and the UTRAN.Generally, the term “radio bearer” refers to radio resources assignedbetween the UE and the UTRAN. And, the term “radio access bearer”generally refers to radio resources assigned between the UE and, e.g.,an SGSN (Serving GPRS Service Node). The present disclosure shall, attimes, refer to the term radio resource, and such term shall refer, asappropriate, to either or both the radio bearer and/or the radio accessbearer.

The problem with the above is that even if an application on the UE hascompleted its data transaction and is not expecting any further dataexchange, it still waits for the network to move it to the correctstate. The network may not be even aware of the fact that theapplication on the UE has completed its data exchange. For example, anapplication on the UE may use its own acknowledgement-based protocol toexchange data with its application server, which is accessed through theUMTS core network. Examples are applications that run over User DatagramProtocol/Internet Protocol (UDP/IP) implementing their own guaranteeddelivery. In such a case, the UE knows whether the application serverhas sent or received all the data packets or not and is in a betterposition to determine if any further data exchange is to take place andhence decide when to terminate the RRC connection associated with PacketService (PS) domain. Since the UTRAN controls when the RRC connectedstate is changed to a different state or into an idle mode and the UTRANis not aware of the status of data delivery between the UE and externalserver, the UE may be forced to stay in a higher data rate state or modethan what is required, possibly resulting in decreased battery life forthe mobile station and also possibly resulting in wasted networkresources due to the fact that the radio resources are unnecessarilybeing kept occupied and are thus not available for another user.

One solution to the above is to have the UE send a signaling releaseindication to the UTRAN when the UE realizes that it is finished with adata transaction. Pursuant to section 8.1.14.3 of the 3GPP TS 25.331specification, the UTRAN may release the signaling connection uponreceipt of the signaling release indication from the UE, causing the UEto transition to an idle mode or some other RRC state. A problem withthe above solution is that the UTRAN might become inundated withsignaling release indication messages from the UE and other UEs.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure will be better understood with reference to thedrawings in which:

FIG. 1 is a block diagram showing RRC states and transitions;

FIG. 2 is a schematic of a UMTS network showing various UMTS cells and aURA;

FIG. 3 is a block diagram showing the various stages in an RRCconnection setup;

FIG. 4A is a block diagram of an exemplary transition between a CELL_DCHconnected mode state and an idle mode initiated by the UTRAN accordingto current method;

FIG. 4B is a block diagram showing an exemplary transition between aCELL_DCH state connected mode transition to an idle mode utilizingsignaling release indications;

FIG. 5A is a block diagram of an exemplary transition between a CELL_DCHinactivity state to a CELL_FACH inactivity state to an idle modeinitiated by the UTRAN;

FIG. 5B is a block diagram of an exemplary transition between CELL_DCHinactivity state and an idle mode utilizing signaling releaseindications;

FIG. 6 is a block diagram of a UMTS protocol stack;

FIG. 7 is an exemplary UE that can be used in association with thepresent method;

FIG. 8 is an exemplary network for use in association with the presentmethod and system;

FIG. 9 is a flow diagram showing the steps of adding a cause for asignaling connection release indication at the UE;

FIG. 10 is a flow diagram showing the steps taken by a UE upon receiptof a signaling connection release indication having a cause;

FIG. 11 illustrates a graphical representation of exemplary logical andphysical channel allocation during exemplary operation of the networkshown in FIG. 8 in which multiple, concurrent packet data communicationservice sessions are provided with the UE;

FIG. 12 illustrates a functional block diagram of UE and networkelements that provide for radio resource release function to releaseradio resources of individual packet data services pursuant to anembodiment of the present disclosure;

FIG. 13 illustrates a message sequence diagram representative ofsignaling generated pursuant to operation of an embodiment of thepresent disclosure by which to release radio resource allocation to aPDP context;

FIG. 14 illustrates a message sequence diagram, similar to that shown inFIG. 13, also representative of signaling generated pursuant tooperation of an embodiment of the present disclosure by which to releaseradio resource allocation;

FIG. 15 illustrates a process diagram representative of the process ofan embodiment of the present disclosure;

FIG. 16 illustrates a method flow diagram illustrating the method ofoperation of an embodiment of the present disclosure;

FIG. 17 illustrates a method flow diagram, also illustrating the methodof operation of an embodiment of the present disclosure;

FIG. 18 illustrates a method flow diagram of an embodiment in whichtransitioning decisions are made based on a Radio Resource Profile at anetwork element;

FIG. 19 illustrates a simplified block diagram of a network elementcapable of being used with the method of FIG. 18;

FIG. 20 illustrates a data flow diagram for the sending of a transitionindication or request message;

FIG. 21 illustrates a data flow diagram for setting an inhibit timervalue at a UE;

FIG. 22 illustrates a signaling connection release indication procedure,normal case;

FIG. 23 illustrates a signaling connection release indication procedure,normal case;

FIG. 24 illustrates a cell update procedure, basic flow;

FIG. 25 illustrates a cell update procedure with update of UTRANmobility information;

FIG. 26 illustrates a cell update procedure with physical channelreconfiguration;

FIG. 27 illustrates a cell update procedure with transport channelreconfiguration;

FIG. 28 illustrates a cell update procedure with radio bearer release;

FIG. 29 illustrates a cell update procedure with radio bearerreconfiguration;

FIG. 30 illustrates a cell update procedure with radio bearer setup;

FIG. 31 illustrates a cell update procedure, failure case;

FIG. 32 illustrates a URA update procedure, basic flow;

FIG. 33 illustrates a URA update procedure with update of UTRAN mobilityinformation;

FIG. 34 illustrates a URA update procedure, failure case;

FIG. 35 illustrates a signalling connection release indicationprocedure, normal case;

FIG. 36 illustrates a cell update procedure, basic flow;

FIG. 37 illustrates a cell update procedure with update of UTRANmobility information;

FIG. 38 illustrates a cell update procedure with physical channelreconfiguration;

FIG. 39 illustrates a cell update procedure with transport channelreconfiguration;

FIG. 40 illustrates a cell update procedure with radio bearer release;

FIG. 41 illustrates a cell update procedure with radio bearerreconfiguration;

FIG. 42 illustrates a cell update procedure with radio bearer set up;

FIG. 43 illustrates a cell update procedure, failure case;

FIG. 44 illustrates a URA update procedure, basic flow;

FIG. 45 illustrates a URA update procedure with update of UTRAN mobilityinformation; and

FIG. 46 illustrates a URA update procedure, failure case.

DETAILED DESCRIPTION

According to one aspect of the present application, there is provided amethod performed by a user equipment (UE), the method comprising: at theUE, maintaining a count of how many indication messages with a cause sethave been sent by the UE while in at least one radio resource control(RRC) state; receiving packet switched (PS) data by the UE; resettingthe count by the UE responsive to receiving the PS data.

According to another aspect of the present application, there isprovided a user equipment (UE) configured to: maintain a count of howmany indication messages with a cause set have been sent by the UE whilein at least one radio resource control (RRC) state; receive packetswitched (PS) data; reset the count responsive to receiving the PS data.

According to another aspect of the present application, there isprovided a method performed by a user equipment (UE), the methodcomprising: at the UE, maintaining a count of how many indicationmessages with a cause set have been sent by the UE while in at least oneradio resource control (RRC) state; transmitting packet switched (PS)data; resetting the count by the UE responsive to transmitting the PSdata.

According to another aspect of the present invention, there is provideda user equipment (UE) configured to: maintain a count of how manyindication messages with a cause set have been sent by the UE while inat least one radio resource control (RRC) state; transmit packetswitched (PS) data; reset the count by the UE responsive to thetransmission of PS data.

According to another aspect of the present invention, there is provideda method performed by a user equipment (UE), the method comprising: atthe UE, maintaining a count of how many indication messages with a causeset have been sent by the UE while in at least one radio resourcecontrol (RRC) state; transmitting signaling by the UE on radio bearer 3(RB3) or upward; resetting the count by the UE responsive to thetransmission of signaling.

According to another aspect of the present invention, there is provideda user equipment (UE) configured to: maintain a count of how manyindication messages with a cause set have been sent by the UE while inat least one radio resource control (RRC) state; transmit signaling onradio bearer 3 (RB3) or upward; reset the count responsive to thetransmission of signaling.

According to another aspect of the present invention, there is provideda method performed by a user equipment (UE), the method comprising: atthe UE, maintaining a count of how many indication messages with a causeset have been sent by the UE while in at least one radio resourcecontrol (RRC) state; entering RRC Connected mode; resetting the countresponsive to entering RRC Connected mode.

According to another aspect of the present invention, there is provideda user equipment (UE) configured to: maintain a count of how manyindication messages with a cause set have been sent by the UE while inat least one radio resource control (RRC) state; enter RRC Connectedmode; reset the count responsive to entering RRC Connected mode.

According to another aspect of the present application, there isprovided a method performed by a user equipment (UE), the methodcomprising: at the UE, maintaining a count of how many indicationmessages with a cause set have been sent by the UE while in at least oneradio resource control (RRC) state; receiving a paging message thattriggers a cell update procedure; resetting the count by the UEresponsive to receiving the paging message.

In some embodiments of any of the above summarized aspects, thesignaling comprises uplink radio link control (RLC) control protocoldata unit (PDU).

In some embodiments of any of the above summarized aspects, theindication messages comprise signaling connection release indicationmessages.

In some embodiments of any of the above summarized aspects, theindication messages in the count each have a cause set to “UE RequestedPS Data session end”.

In some embodiments of any of the above summarized aspects, the cause isset to “UE Requested PS Data session end”.

In some embodiments of any of the above summarized aspects, the at leastone RRC state comprises a CELL_PCH state or a URA_PCH state.

In some embodiments of any of the above summarized aspects, maintaininga count comprises using a counter.

In some embodiments the receiving a paging message comprises: receivinga PAGING TYPE 1 message fulfilling the conditions for initiating a cellupdate procedure.

The examples and embodiments provided below describe various methods andsystems for transitioning a User Equipment (UE) or other mobile devicebetween various states/modes of operation in a wireless network such as,for example, a UMTS network. It is to be understood that otherimplementations in other types of networks are also possible. Forexample, the same teachings could also be applied to aCode-Division-Multiple-Access (CDMA) network (e.g. 3GPP2 IS-2000),Wideband-CDMA (W-CDMA) network (e.g. 3GPP UMTS/High-Speed Packet Access(HSPA)) network, an Evolved UTRAN network (e.g. LTE), or by way ofgeneralization, to any network based on radio access technologies thatutilize network-controlled radio resources or that does not maintain anyknowledge of the status of device application level data exchanges. Thespecific examples and implementations described below although presentedfor simplicity in relation to UMTS networks are also applicable to theseother network environments. Further, the network element is sometimesdescribed below as the UTRAN. However, if other network types besidesUMTS are utilized, the network element can be selected appropriatelybased on the network type. Further, the network element can be the corenetwork in a UMTS system or any other appropriate network system, wherethe network element is the entity that makes transition decisions.

In a particular example, the present system and method provide for thetransitioning from an RRC connected mode to a more battery efficient orradio resource efficient state or mode while providing for decisionmaking capabilities at the network. In particular, the present methodand apparatus provide for transitioning based on receipt of anindication from a UE indicating, either implicitly or explicitly, that atransition of the RRC state or mode associated with a particularsignaling connection with radio resources to another state or modeshould occur. As will be appreciated, such a transition indication orrequest could utilize an existing communication under current standards,for example a SIGNALING CONNECTION RELEASE INDICATION message, or couldbe a new dedicated message to change the state of the UE, such as a“preferred RRC state request” or a “data transfer complete indicationmessage”. A data transfer complete indication message is a message whichindicates the completion of higher layer data transfer. As used herein,an indication could refer to either scenario, and could incorporate arequest.

The transition indication originated by the UE can be sent in somesituations when one or more applications on the UE have completed anexchange of data and/or when a determination is made that the UEapplication(s) are not expected to exchange any further data. Thenetwork element can then use the indication and any information providedtherein, as well as other information related to the radio resource,such a quality of service, Access Point Name (APN), Packet Data Protocol(PDP) context, historical information, among others, defined herein as aradio resource profile, to make a network specific decision aboutwhether to transition the mobile device to another mode or state, or donothing. The transition indication provided by the UE or mobile devicecan take several forms and can be sent under different conditions. In afirst example, the transition indication can be sent based on acomposite status of all of the applications residing on the UE.Specifically, in a UMTS environment, if an application on the UEdetermines that it is done with the exchange of data, it can send a“done” indication to a “connection manager” component of UE software.The connection manager can, in one embodiment, keep track of allexisting applications (including those providing a service over one ormultiple protocols), associated Packet Data Protocol (PDP) contexts,associated packet switched (PS) radio resources and associated circuitswitched (CS) radio resources. A PDP Context is a logical associationbetween a UE and PDN (Public Data Network) running across a UMTS corenetwork. One or multiple applications (e.g. an e-mail application and abrowser application) on the UE may be associated with one PDP context.In some cases, one application on the UE is associated with one primaryPDP context and multiple applications may be tied with secondary PDPcontexts. The Connection Manager receives “done” indications fromdifferent applications on the UE that are simultaneously active. Forexample, a user may receive an e-mail from a push server while browsingthe web. After the e-mail application has sent an acknowledgment, it mayindicate that it has completed its data transaction. The browserapplication may behave differently and instead make a predictivedetermination (for e.g. using an inactivity timer) of when to send a“done” indication to the connection manager.

Based on a composite status of such indications from activeapplications, UE software can decide to send a transition indication toindicate or request of the network that a transition from one state ormode to another should occur. Alternatively, the UE software can insteadwait before it sends the transition indication and introduce a delay toensure that the application is truly finished with data exchange anddoes not require to be maintained in a battery or radio resourceintensive state or mode. The delay can be dynamic based on traffichistory and/or application profiles. Whenever the connection managerdetermines with some probability that no application is expected toexchange data, it can send a transition indication to the network toindicate that a transition should occur. In a specific example, thetransition indication can be a signaling connection release indicationfor the appropriate domain (e.g. PS domain) to request a transition toan idle mode. Alternatively, the transition indication could be arequest for state transition within connected mode to the UTRAN.

As described below in further detail, based on the receipt of atransition indication and optionally a radio resource profile, a networkelement such as the UTRAN in a UMTS environment can decide to transitionthe UE from one state or mode to another.

Other transition indications are possible. For example, instead ofrelying on a composite status of all active applications on the UE, theUE software can, in an alternative embodiment, send a transitionindication every time a UE application has completed an exchange or dataand/or the application is not expected to exchange further data. In thiscase, the network element (e.g. the UTRAN), based on an optional radioresource profile for the UE as described with reference to FIG. 18below, can utilize the indication to make a transitioning decision.

In yet another example, the transition indication could simply indicatethat one or more applications on the UE completed a data exchange and/orthat the UE application(s) are not expected to exchange any furtherdata. Based on that indication and an optional radio resource profilefor the UE, the network (e.g. UTRAN), can decide whether or not totransition the UE to a more appropriate state or mode or operation.

In a further example, the transition indication could be implicit ratherthan explicit. For example, the indication may be part of a statusreport sent periodically. Such a status report could include informationsuch as whether a radio link buffer has data or could includeinformation on outbound traffic.

When the UE sends a transition indication it may include additionalinformation in order to assist the network element in making a decisionto act on the indication. This additional information would include thereason or cause for the UE to send the message. This cause or reason(explained below in greater detail) would be based on the UE determininga need for “fast dormancy” like behavior. Such additional informationmay be by way of a new information element or a new parameter within thetransition indication message.

In a further embodiment, a timer could exist on the UE to ensure that atransition indication may not be sent until a time duration has elapsed(inhibit duration) since a previous transition indication was sent. Thisinhibit timer restricts the UE from sending the transition indicationmessage too frequently and further allows the network to make adetermination by relying on messages that are triggered only with agiven maximum frequency. The time duration could be determined by atimer whose value is preconfigured, or set by a network (indicated orsignaled). If the value is set by a network, it could be conveyed in newor existing messages such as RRC Connection Request, RRC Connectionrelease, Radio Bearer Setup, UTRAN Mobility Information or a SystemInformation Block, among others, and could be an information element inthose messages. The value could alternatively be conveyed in an inhibittransition indication portion of an RRC connection setup message sent bythe UTRAN in response to an RRC connection request message received fromthe UE, for example.

In an alternative embodiment, the value could be conveyed to a UE in amessage whose type depends on a state of the UE. For example, thenetwork could send the value to all the UEs in a cell as a portion of asystem information message which is read by the UE when it is in anIDLE, URA_PCH, Cell_PCH or CELL_FACH state.

In yet another embodiment, the value could be sent as a portion of anRRC connection setup message.

Network generated messages may also convey an implied inhibit timervalue through non-inclusion of an inhibit timer in the message or in aninformation element within the message. For example, upon determiningthat an inhibit timer is omitted from a received message, a UE applies apre-determined value for use as an inhibit timer value. One exemplaryuse of inhibit timer value omission is to prohibit the UE from sending atransition indication message. In such a situation, when a UE detectsthe omission of an expected inhibit timer value in a received message,the UE may, based on the omission, be prohibited from sending anytransition indication messages. One way to achieve this is for the UE toadopt an inhibit timer value of infinity.

In another embodiment when the UE detects the omission of an inhibittimer value (and for example, adopts an inhibit timer value ofinfinity), it may send transition indications but without including anyadditional information, specifically it may omit the cause fortriggering the sending of the transition indication (further describedbelow in greater detail). The omission of a cause element in atransition indication message may ensure backward-compatibility byallowing UEs to use an existing transition indication message (e.g.SIGNALING CONNECTION RELEASE INDICATION) to request or indicate atransition.

Non-inclusion of an inhibit timer in the received message is furtherdetailed with reference to an exemplary embodiment wherein a SystemInformation Block is broadcast in a cell, or sent to a UE and the SystemInformation Block is configured to convey an inhibit timer value. Inthis embodiment, if the UE receives a System Information Block whichdoes not contain an inhibit timer, known as T3xx, in the message or aninformation element within the message, in which case the UE maydetermine to not enable the UE to send the transition indicationmessage, for example by setting the inhibit timer, T3xx, to infinity.

Non-inclusion of an inhibit timer is further detailed with reference toanother exemplary embodiment wherein an inhibit timer, T3xx, is omittedfrom a UTRAN Mobility Information message. In such a situation arecipient UE may continue to apply a previous stored inhibit timervalue. Alternatively, the UE, on detecting the omission of the inhibittimer T3xx, may determine to not enable the UE to send the transitionindication message, for example by setting the inhibit timer, T3xx, toinfinity.

In yet another exemplary embodiment, a UE, on detecting the omission ofan inhibit timer in the received message or in an information elementwithin the message, sets the inhibit timer value to another preset value(e.g. one of 0 seconds, 5 seconds, 10 seconds, 15 seconds, 20 seconds,30 seconds, 1 minute, 1 minute 30 seconds, 2 minutes). Alternatively orin addition, these examples may apply to other network generatedmessages.

In other embodiments, if the inhibit timer (value) is not sent orsignaled to the UE in a message or information element, or the inhibittimer is not read from broadcast system information or received fromother dedicated UTRAN messages on transitioning from one cell toanother, the sending of a transition indication may or may not occur.

Specifically, in one embodiment, the UE, on detecting that there is noinhibit timer present, does not initiate a transition indication basedon a higher layer determining that it has no more PS data to transmit.

In an alternative embodiment, the UE on detecting that there is noinhibit timer present, may initiate a transition indication based on thehigher layer determining that it has no more PS data to transmit.

In yet another embodiment, if no timer value is received from the UTRANwithin a message, or within an information element in a message (viabroadcasting or otherwise), rather than setting the timer value at theUE to infinity the UE may set the inhibit timer to zero or alternativelydelete any configuration for the timer, and instead be permitted to senda transition indication. In this case, the UE could omit or beprohibited from attaching a cause in the transition indication message.In one embodiment a SIGNALING CONNECTION RELEASE INDICATION message isused as one example of a transition indication.

In an embodiment, the transition indication is conveyed using thesignaling connection release indication procedure. The signalingconnection release indication procedure is used by the UE to indicate tothe UTRAN that one of its signaling connections has been released.

Specifically in accordance with TS 25.331 Section 8.1.14.2 the UE shall,on receiving a request to release the signaling connection from theupper layers for a specific CN domain, check if the signaling connectionin the variable “ESTABLISHED_SIGNALLING_CONNECTIONS for the specific CNdomain identified in the information element “CN domain identity”exists. If it does, the UE may initiate the signaling connection releaseindication procedure.

In the case of the inhibit timer value not being signaled or otherwiseconveyed to the UE, no signaling connection release indication cause isspecified in the SIGNALING CONNECTION RELEASE INDICATION message. Thoseskilled in the art will appreciate that in this alternative embodimentthe lack of a timer value does not result in the timer value being setto infinity.

On the UTRAN side, upon receipt of a SIGNALING CONNECTION RELEASEINDICATION message without a cause, the UTRAN indicates the release ofthe signaling connection for the identified CN domain identity to theupper layers. This may then initiate the release of the establishedradio resource control connection.

Under another alternative embodiment, when the UTRAN signals or conveysa timer value to the UE, for example, inhibit timer T3xx in informationelement “UE timers and constants in connected mode” (or using systeminformation, such as SIB1, SIB3 or SIB4, or with a dedicated UTRANmobility information message), the release procedure occurs inaccordance with the following. First, the UE can check whether there areany circuit switched domain connections indicated. Such connections maybe indicated in the variable “ESTABLISHED_-SIGNALLING_CONNECTIONS”. Ifthere are no circuit switched domain connections, a second check todetermine whether an upper layer indicates that there will be no packetswitched domain data for a prolonged period could occur.

If there are no circuit switched domain connections and no packetswitched domain data is expected for a prolonged period, the UE may nextcheck whether the timer T3xx is running.

If the timer T3xx is not running, the UE sets information element “CNDomain Identity” to the packet switched (PS) domain. Further, theinformation element “Signaling Connection Release Indication Cause” isset to “UE requested PS data session end”. The SIGNALING CONNECTIONRELEASE INDICATION message is transmitted on the DCCH using AM RLC.Further, after the transmission the timer T3xx is started.

The procedure above ends on successful delivery of the SIGNALINGCONNECTION RELEASE INDICATION message, as confirmed by the RLC in theabove procedure. In this embodiment, the UE is inhibited from sendingthe SIGNALING CONNECTION RELEASE INDICATION message with a signalingconnection release indication cause set to “UE Requested PS data sessionend” while the timer T3xx is running or until the timer T3xx hasexpired.

When the T3xx timer is running, if the signaling connection releaseindication procedure is initiated due to no further packet switcheddomain data for a prolonged duration, the UE is responsible forimplementing whether to initiate the procedure on the expiry of the T3xxtimer. The UE decision may be based on determining whether it has anysubsequent signaling connection release indication or request messagesto send and if so, the UE decision may include re-checking some or allof the same checks for initiating the procedure as outlined herein.

On the UTRAN side, if the SIGNALING CONNECTION RELEASE INDICATIONmessage received does not include a signaling connection releaseindication cause, the UTRAN may request the release of the signalingconnection from an upper layer and the upper layer may then initiate therelease of the signaling connection. If on the other hand the SIGNALINGCONNECTION RELEASE INDICATION message received includes a cause, theUTRAN may either release the signaling connection or initiate a statetransition to a more battery efficient state (e.g. CELL_FACH, CELL_PCH,URA_PCH or IDLE_MODE).

The inhibit duration above may be based on the state the UE would liketo transition to. For example the inhibit duration may be different,whether the mobile indicated its last preference for some RRCStates/modes versus others. For example, it could be different if themobile indicated a preference for idle mode, versus Cell_FACH, or versusCell_PCH/URA_PCH States. In the case where the Inhibit Duration is setby the network, this may be achieved by the network indicating/sendingtwo (or more) sets of values to the mobile, to be used depending on thescenario. Alternatively, the indication could be done in such a way thatthe appropriate Inhibit duration value only is indicated/signaled to themobile: for example, if the UE wants to transition to Cell_PCH, adifferent elapsed time duration could be set than if the UE wants totransition to Idle.

The inhibit duration from above may be different, depending on which RRCState/mode the mobile currently is in (e.g. Cell_DCH/Cell_FACH versusCell_PCH/URA_PCH, or in Cell_DCH versus Cell_FACH, or Cell_PCH/URA_PCH).

The inhibit duration from above may be different, depending if thenetwork has already acted on preference RRC State information from themobile. Such recognition may happen on the network, or on the mobileside. In the first case, this may affect the Inhibit valuesindicated/signaled by the network to the mobile. In this second case,different sets of Inhibit duration values may be preconfigured orindicated/signaled by the network. As a particular case, the inhibitduration/functionality may be reduced or cancelled if the network hasacted on preference RRC State information from the mobile, e.g. hasinitiated a state transition to a state indicated by the UE.

The inhibit duration from above may be different, depending on, forexample, preferences, features, capabilities, loads or capacities of thenetwork. A network may indicate a short inhibit duration if it is ableto receive frequent transition indication messages. A network mayindicate a long inhibit duration if it is unable or does not want toreceive frequent transition indication messages. A network may indicatea specific period of time during which a UE cannot send transitionindication messages. The specific period of time can be indicatednumerically (i.e. 0 seconds, 30 seconds, 1 minute, 1 minute 30 seconds,2 minutes or infinity) for example. A UE which receives an inhibitduration of 0 seconds is able to send transition indications withoutdelay. A UE which receives an inhibit duration of infinity is unable tosend transition indications.

A maximum number of messages per time-window (e.g. “no more than 15messages every 10 minutes”) may be used/specified instead of, or inaddition to, the Inhibit duration.

Combinations of the above inhibition durations/maximum messages pertime-window are possible.

By way of example, the present disclosure generally describes thereception of an RRC CONNECTION REQUEST message by a UTRAN from a UE.Upon receiving an RRC CONNECTION REQUEST message, the UTRAN should, forexample, accept the request and send an RRC CONNECTION SETUP message tothe UE. The RRC CONNECTION SETUP message may include an InhibitTransition Indication, which is known as Timer T3xx. Upon reception ofthe RRC CONNECTION SETUP message by the UE, the UE should, for example,store the value of the Timer T3xx, replacing any previously storedvalue, or, if the Timer T3xx is not in the RRC CONNECTION SETUP message,set the value of the timer to infinity. In some embodiments, the RRCCONNECTION SETUP message must include an Inhibit Transition Indicationto ensure that the UE knows that the UTRAN supports the InhibitTransition Indication signaling.

In an embodiment, it is assumed that during mobility in a DCH state, theUE will maintain its currently stored value for the inhibit timer. Insome cases where the inhibit timer is set to infinity this may mean thatthe UE must wait for network data inactivity timers to expire and forthe network to move the UE to an RRC state where it can receive ordetermine a new value for the inhibit timer. In other cases where theinhibit timer is some value other than infinity before the handover,this other value is continued to be used until the UE is able to updatethe timer value to that indicated in the new cell.

In some instances the inhibit timer and the transition indication (e.g.SIGNALING CONNECTION RELEASE INDICATION) message may not be implementedin some networks or in some cells within a network. For mobilitypurposes, if there is no support available for the feature of sending atransition indication or request message (particularly in the case wherea cause is used), the UE should default to not sending the message. Thisavoids unnecessary transmissions and the associated waste of networkresources and battery resources.

In addition, for mobility purposes, different vendor's network equipmentused within a network may lead to adjacent cells using different inhibittimers which need to be updated on the UE when the UE moves betweencells.

In one alternative embodiment this is handled by providing that allhandover and related bearer control messages include a value for aninhibit timer T3xx. Such messages are referred to herein as mobilitymessages. This allows the UE to receive new inhibit timer values whenmoving between cells. It also allows the UE to set a default timer valuefor the inhibit timer if one of these mobility messages does not containan inhibit timer value. As will be appreciated, if no inhibit timervalue is received in the mobility messages, this indicates that the cellis not enabled for fast dormancy.

As another example of a transition indication procedure, a Data TransferComplete Indication procedure may be used by the UE to indicate to theUTRAN that it has determined that it does not need to transfer any morePS domain data. In connection with the example described above, the UEwould not send the Data Transfer Complete Indication message before thetimer T3xx has expired, if the timer T3xx was running.

The Data Transfer Complete Indication procedure commences with anindication that the RRC or upper layers will have no more PS domain datafor a prolonged duration. If a CS domain connection is indicated in thevariable ESTABLISHED_SIGNALLING_CONNECTIONS or if timer T3xx is set toinfinity, the procedure ends. Otherwise if timer T3xx is not running(i.e. has expired) or is set to 0 seconds, a DATA TRANSFER COMPLETEINDICATION message is submitted to the lower layers for transmissionusing AM RLC on DCCH after which the timer T3xx is started or reset whenthe message has been delivered to the lower layers;

The UTRAN on receipt of the DATA TRANSFER COMPLETE INDICATION may decideto initiate a UE transition to a more battery efficient RRC state oridle mode.

The UE shall not send the Data Transfer Complete Indication messagewhile timer T3xx is running.

The present disclosure provides method to control use of a transitionindication message by a user equipment, comprising including an inhibittransition indication in a configuration message; and sending theconfiguration message with the inhibit transition indication to the userequipment.

The present disclosure further provides a network element configured tocontrol use of a transition indication message by a user equipment, thenetwork element configured to: include an inhibit transition indicationin a configuration message; and send the configuration message with theinhibit transition indication to the user equipment.

The present disclosure further provides a method at a user equipment(UE) for sending a transition indication, the method comprising settinga timer according to an inhibit transition indication received from anetwork element; detecting that a data transfer is complete; and sendingthe transition indication upon detecting that the timer is not running.

The present disclosure still further provides user equipment configuredto send a transition indication, the user equipment configured to: set atimer according to an inhibit transition indication received from anetwork element; detect that a data transfer is complete; and send thetransition indication upon detecting that the timer is not running.

Reference is now made to FIG. 1. FIG. 1 is a block diagram showing thevarious modes and states for the radio resource control portion of aprotocol stack in a UMTS network. In particular, the RRC can be eitherin an RRC idle mode 110 or an RRC connected mode 120.

As will be appreciated by those skilled in the art, a UMTS networkconsists of two land-based network segments. These are the Core Network(CN) and the Universal Terrestrial Radio-Access Network (UTRAN) (asillustrated in FIG. 8). The Core Network is responsible for theswitching and routing of data calls and data connections to the externalnetworks while the UTRAN handles all radio related functionalities.

In idle mode 110, the UE must request an RRC connection to set up theradio resource whenever data needs to be exchanged between the UE andthe network. This can be as a result of either an application on the UErequiring a connection to send data, or as a result of the UE monitoringa paging channel to indicate whether the UTRAN or SGSN has paged the UEto receive data from an external data network such as a push server. Inaddition, the UE also requests an RRC connection whenever it needs tosend Mobility Management signaling messages such as Location AreaUpdate.

Once the UE has sent a request to the UTRAN to establish a radioconnection, the UTRAN chooses a state for the RRC connection to be in.Specifically, the RRC connected mode 120 includes four separate states.These are CELL_DCH state 122, CELL_FACH state 124, CELL_PCH state 126and URA_PCH state 128.

From idle mode 110 the UE autonomously transitions to the CELL_FACHstate 124, in which it makes its initial data transfer, subsequent towhich the network determines which RRC connected state to use forcontinued data transfer. This may include the network either moving theUE into the Cell Dedicated Channel (CELL_DCH) state 122 or keeping theUE in the Cell Forward Access Channel (CELL_FACH) state 124.

In CELL_DCH state 122, a dedicated channel is allocated to the UE forboth uplink and downlink to exchange data. This state, since it has adedicated physical channel allocated to the UE, typically requires themost battery power from the UE.

Alternatively, the UTRAN can maintain the UE in a CELL_FACH state 124.In a CELL_FACH state no dedicated channel is allocated to the UE.Instead, common channels are used to send signaling in a small amount ofbursty data. However, the UE still has to continuously monitor the FACH,and therefore it consumes more battery power than in a CELL_PCH state, aURA_PCH state, and in idle mode.

Within the RRC connected mode 120, the RRC state can be changed at thediscretion of the UTRAN. Specifically, if data inactivity is detectedfor a specific amount of time or data throughput below a certainthreshold, is detected, the UTRAN may move the RRC state from CELL_DCHstate 122 to the CELL_FACH state 124, CELL_PCH state 126 or URA_PCHstate 128. Similarly, if the payload is detected to be above a certainthreshold, then the RRC state can be moved from CELL_FACH state 124 toCELL_DCH state 122.

From CELL_FACH state 124, if data inactivity is detected for apredetermined time in some networks, the UTRAN can move the RRC statefrom CELL_FACH state 124 to a paging channel (PCH) state. This can beeither the CELL_PCH state 126 or URA_PCH state 128.

From CELL_PCH state 126 or URA_PCH state 128 the UE must move toCELL_FACH state 124 in order to initiate an update procedure to requesta dedicated channel. This is the only state transition that the UEcontrols.

Idle mode 110 and CELL_PCH state 126 and URA_PCH state 128 use adiscontinuous reception cycle (DRX) to monitor broadcast messages andpages by a Paging Indicator Channel (PICH). No uplink activity ispossible.

The difference between CELL_PCH state 126 and URA_PCH state 128 is thatthe URA_PCH state 128 only triggers a URA Update procedure if the UE'scurrent UTRAN registration area (URA) is not among the list of URAidentities present in the current cell. Specifically, reference is madeto FIG. 2. FIG. 2 shows an illustration of various UMTS cells 210, 212and 214. All of these cells require a cell update procedure ifreselected to a CELL_PCH state. However, in a UTRAN registration area,each will be within the same UTRAN registration area (URA) 320, and thusa URA update procedure is not triggered when moving between 210, 212 and214 when in a URA_PCH mode.

As seen in FIG. 2, other cells 218 are outside the URA 320, and can bepart of a separate URA or no URA.

As will be appreciated by those skilled in the art, from a battery lifeperspective the idle state provides the lowest battery usage comparedwith the states above. Specifically, because the UE is required tomonitor the paging channel only at intervals, the radio does not need tocontinuously be on, but will instead wake up periodically. The trade-offfor this is the latency to send data. However, if this latency is nottoo great, the advantages of being in the idle mode and saving batterypower outweigh the disadvantages of the connection latency.

Reference is again made to FIG. 1. Various UMTS infrastructure vendorsmove between states 122, 124, 126 and 128 based on various criteria.These criteria could be the network operator's preferences regarding thesaving of signaling or the saving of radio resources, among others.Exemplary infrastructures are outlined below.

In a first exemplary infrastructure, the RRC moves between an idle modeand a Cell_DCH state directly after initiating access in a CELL_FACHstate. In the Cell₁₃ DCH state, if two seconds of inactivity aredetected, the RRC state changes to a Cell_FACH state 124. If, inCell_FACH state 124, ten seconds of inactivity are detected then the RRCstate changes to Cell_PCH state 126. Forty five minutes of inactivity inCell_PCH state 126 will result in the RRC state moving back to idle mode110.

In a second exemplary infrastructure, RRC transition can occur betweenan idle mode 110 and connected mode 120 depending on a payloadthreshold. In the second infrastructure, if the payload is below acertain threshold then the UTRAN moves the RRC state to CELL_FACH state124. Conversely, if the data payload is above a certain payloadthreshold then the UTRAN moves the RRC state to a CELL_DCH state 122. Inthe second infrastructure, if two minutes of inactivity are detected inCELL_DCH state 122, the UTRAN moves the RRC state to CELL_FACH state124. After five minutes of inactivity in the CELL_FACH state 124, theUTRAN moves the RRC state to CELL_PCH state 126. In CELL_PCH state 126,two hours of inactivity are required before moving back to idle mode110.

In a third exemplary infrastructure, movement between idle mode 110 andconnected mode 120 is always to CELL_DCH state 122. After five secondsof inactivity in CELL_DCH state 122 the UTRAN moves the RRC state toCELL_FACH state 124. Thirty seconds of inactivity in CELL_FACH state 124results in the movement back to idle mode 110.

In a fourth exemplary infrastructure the RRC transitions from an idlemode to a connected mode directly into a CELL_DCH state 122. In thefourth exemplary infrastructure, CELL_DCH state 122 includes twoconfigurations. The first includes a configuration which has a high datarate and a second configuration includes a lower data rate, but stillwithin the CELL_DCH state. In the fourth exemplary infrastructure, theRRC transitions from idle mode 110 directly into the high data rateCELL_DCH sub-state. After 10 seconds of inactivity the RRC statetransitions to a low data rate CELL_DCH sub-state. Seventeen seconds ofinactivity from the low data sub-state of CELL_DCH state 122 results inthe RRC state changing it to idle mode 110.

The above four exemplary infrastructures show how various UMTSinfrastructure vendors are implementing the states. As will beappreciated by those skilled in the art, in each case, if the time spenton exchanging actual data (such as an email) is significantly shortcompared to the time that is required to stay in the CELL_DCH or theCELL_FACH states. This causes unnecessary current drain, making the userexperience in newer generation networks such as UMTS worse than in priorgeneration networks such as GPRS.

Further, although the CELL_PCH state 126 is more optimal than theCELL_FACH state 124 from a battery life perspective, the DRX cycle in aCELL_PCH state 126 is typically set to a lower value than the idle mode110. As a result, the UE is required to wake up more frequently in theCELL_PCH state 126 than in an idle mode 110.

The URA_PCH state 128 with a DRX cycle similar to that of the idle state110 is likely the optimal trade up between battery life and latency forconnection. However, URA_PCH state 128 is currently not implemented inthe UTRAN. In some cases, it is therefore desirable to quicklytransition to the idle mode as quickly as possible after an applicationis finished with the data exchange, from a battery life perspective.

Reference is now made to FIG. 3. When transitioning from an idle mode toa connected mode various signaling and data connections need to be made.Referring to FIG. 3, the first item to be performed is an RRC connectionsetup 310. As indicated above, this RRC connection setup 310 can only betorn down by the UTRAN.

Once RRC connection setup 310 is accomplished, a signaling connectionsetup 312 is started.

Once signaling connection setup 312 is finished, a ciphering andintegrity setup 314 is started. Upon completion of this, a radio bearersetup 316 is accomplished. At this point, data can be exchanged betweenthe UE and UTRAN.

Tearing down a connection is similarly accomplished in the reverseorder, in general. The radio bearer setup 316 is taken down and then theRRC connection setup 310 is taken down. At this point, the RRC movesinto idle mode 110 as illustrated in FIG. 1.

Although the current 3GPP specification does not allow the UE to releasethe RRC connection or indicate its preference for RRC state, the UE canstill indicate termination of a signaling connection for a specifiedcore network domain such as the Packet Switched (PS) domain used bypacket-switched applications. According to section 8.1.14.1 of 3GPP TS25.331, the SIGNALING CONNECTION RELEASE INDICATION procedure is used bythe UE to indicate to the UTRAN that one of its signaling connectionshas been released. This procedure may in turn initiate the RRCconnection release procedure.

Thus staying within the current 3GPP specifications, signalingconnection release may be initiated upon the tearing down of thesignaling connection setup 312. It is within the ability of the UE totear down signaling connection setup 312, and this in turn according tothe specification “may” initiate the RRC connection release.

As will be appreciated by those skilled in the art, if signalingconnection setup 312 is torn down, the UTRAN will also need to clean updeciphering and integrity setup 314 and radio bearer setup 316 after thesignaling connection setup 312 has been torn down.

If signaling connection setup 312 is torn down, the RRC connection setupis typically brought down by the network for current vendorinfrastructures if no CS connection is active.

Using this for one of the specific transition indication examplesmentioned above, if the UE determines that it is done with the exchangeof data, for example if a “connection manager” component of the UEsoftware is provided with an indication that the exchange of data iscomplete, then the connection manager may determine whether or not totear down the signaling setup 312. For example, an email application onthe device sends an indication that it has received an acknowledgementfrom the push email server that the email was indeed received by thepush server. The connection manager can, in one embodiment, keep trackof all existing applications, associated PDP contexts, associated PSradio resources and associated circuit switched (CS) radio bearers. Inother embodiments a network element (e.g. the UTRAN) can keep track ofexisting applications, associated PDP contexts, QoS, associated PS radioresources and associated CS radio bearers. A delay can be introduced ateither the UE or network element to ensure that the application(s) is(are) truly finished with data exchange and no longer require an RRCconnection even after the “done” indication(s) has been sent. This delaycan be made equivalent to an inactivity timeout associated with theapplication(s) or the UE. Each application can have its own inactivitytimeout and thus the delay can be a composite of all of the applicationtimeouts. For example, an email application can have an inactivitytimeout of five seconds, whereas an active browser application can havea timeout of sixty seconds. An inhibit duration timer can further delaysending of a transition indication. Based on a composite status of allsuch indications from active applications, as well as a radio resourceprofile and/or inhibit duration timer delay in some embodiments, the UEsoftware decides how long it should or must wait before it sends atransition indication (for e.g. a signaling connection releaseindication or state change request) for the appropriate core network(e.g. PS Domain). If the delay is implemented at the network element,the element makes a determination of whether to and how to transitionthe UE, but only operates the transition after the delay has run itscourse.

The inactivity timeout can be made dynamic based on a traffic patternhistory and/or application profile.

If the network element transitions the UE to idle mode 110, which canhappen in any stage of the RRC connected mode 120 as illustrated in FIG.1, the network element releases the RRC connection and moves the UE toidle mode 110 as illustrated in FIG. 1. This is also applicable when theUE is performing any packet data services during a voice call. In thiscase, the network may choose to release only the PS domain signalingconnection, and maintain the CS domain signaling connection oralternatively may choose not to release anything and instead maintainthe signaling connections to both the PS and CS domains.

In a further embodiment, a cause could be added to the transitionindication indicating to the UTRAN the reason for the indication. In apreferred embodiment, the cause could be an indication that an abnormalstate caused the indication or that the indication was initiated by theUE as a result of a requested transition. Other normal (i.e.non-abnormal) transactions could also result in the sending of thetransition indication.

In a further preferred embodiment, various timeouts can cause atransition indication to be sent for an abnormal condition. The examplesof timers below are not exhaustive, and other timers or abnormalconditions are possible. For example, 10.2.47 3GPP TS 24.008 specifiestimer T3310 as:

TIMER T3310 TIMER TIMER ON THE 1^(st), 2^(nd), 3^(rd), NUM. VALUE STATECAUSE OF START NORMAL STOP 4^(th) EXPIRY Note 3 T3310 15 s GMM-REG-ATTACH REQ sent ATTACH ACCEPT Retransmission INIT received of ATTACH REQATTACH REJECT received

This timer is used to indicate an attachment failure. The failure toattach could be a result of the network or could be a radio frequency(RF) problem such as a collision or bad RF.

The attachment attempt could occur multiple times, and an attachmentfailure results from either a predetermined number of failures or anexplicit rejection.

A second timer of 10.2.47 of 3GPP is timer T3330, which is specified as:

TIMER T3330 TIMER TIMER ON THE 1^(st), 2^(nd), 3^(rd), NUM. VALUE STATECAUSE OF START NORMAL STOP 4^(th) EXPIRY Note 3 T3330 15 s GMM- ROUTINGAREA ROUTING AREA Retransmission ROUTING- UPDATE UPDATE ACC received ofthe ROUTING UPDATING- REQUEST sent ROUTING AREA AREA UPDATE INITIATEDUPDATE REJ received REQUEST message

This timer is used to indicate a routing area update failure. Uponexpiry of the timer, a further routing area update could be requestedmultiple times and a routing area update failure results from either apredetermined number of failures or an explicit rejection.

A third timer of 10.2.47 of 3GPP is timer T3340, which is specified as:

TIMER T3340 TIMER TIMER ON THE 1^(st), 2^(nd), 3^(rd), NUM. VALUE STATECAUSE OF START NORMAL STOP 4^(th) EXPIRY Note 3 T3340 10 s GMM-REG-INITATTACH REJ, DETACH REQ, PS signalling Release the PS (lu modeGMM-DEREG-INIT ROUTING AREA UPDATE REJ or connection signalling only)GMM-RA-UPDATING-INT SERVICE REJ with any of released connection andGMM-SERV-REQ-INIT the causes #11, #12, proceed as (lu mode only) #13 or#15. described in GMM-ATTEMPTING-TO- ATTACH ACCEPT or ROUTING subclauseUPDATE-MM AREA UPDATE ACCEPT is 4.7.1.9 GMM-REG-NORMAL-SERVICE receivedwith “no follow-on proceed” indication.

This timer is used to indicate a GMM service request failure. Uponexpiry of the timer, a further GMM service request could be initiatedmultiple times and a GMM service request failure results from either apredetermined number of failures or an explicit rejection.

Thus, instead of a transition indication cause limited to an abnormalcondition and a release by the UE, the transition indication cause couldfurther include information about which timer failed for an abnormalcondition. In a specific example where a signaling connection releaseindication is used as a transition indication, the indication could bestructured as:

SIGNALING CONNECTION RELEASE INDICATION IE type Information andSemantics Element/Group name Need Multi reference description MessageType MP Message type UE Information Elements Integrity check info CHIntegrity check info 10.3.3.16 CN information elements CN domainidentity MP CN domain identity 10.3.1.1 Signaling Connection OPSignaling t3310 timeout, Release Indication Cause Release t3330 timeout,Indication t3340 timeout, Cause UE Requested Idle Transition

This message is used by the UE to indicate to the UTRAN a request torelease an existing signaling connection. The addition of the signalingconnection release indication cause allows the UTRAN or other networkelement to receive the cause of the signaling connection releaseindication, whether it was due to an abnormal condition, and what theabnormal condition was. Based on the receipt of the SIGNALING CONNECTIONRELEASE INDICATION, an RRC connection release procedure is, in turn,permitted to be initiated at the UTRAN.

In one implementation of this example, the UE, upon receiving a requestto release, or abort, a signaling connection from upper layers for aspecific CN (core network) domain, initiates the signaling connectionrelease indication procedure if a signaling connection is identified ina variable. For example, a variable ESTABLISHED_SIGNALING_CONNECTIONS,for the specific CN domain identified with the IE (information element)“CN domain identity” exists. If the variable does not identify anyexisting signaling connection, any ongoing establishment of a signalingconnection for that specific CN domain is aborted in another manner.Upon initiation of the signaling connection release indicationprocedures in the Cell_PCH or URA_PCH states, the UE performs a cellupdate procedure using a cause “uplink data transmission”. When a cellupdate procedure is completed successfully, the UE continues with thesignaling connection release indication procedures that follow.

Namely, the UE sets the information element (IE) “CN domain identity” tothe value indicated by upper logical layers. The value of the IEindicates the CN domain whose associated signaling connection the upperlayers are marking to be released. If the CN domain identity is set tothe PS domain, and if the upper layer indicates the cause to initiatethis request, then the IE “SIGNALING RELEASE INDICATION CAUSE” isaccordingly set. The UE further removes the signaling connection withthe identity indicated by upper layers from the variable“ESTABLISHED_SIGNALING_CONNECTIONS”. The UE transmits a SIGNALINGCONNECTION RELEASE INDICATION message on, e.g., the Dedicated ControlChannel (DCCH) using acknowledged mode radio link control (AM RLC). Uponconfirmation of successful delivery of the release indication message bythe RLC, the procedure ends.

An IE “Signaling Connection Release Indication Cause is also usedpursuant to an embodiment of the present disclosure. The release causeis aligned, for instance, with existing message definitions. The upperlayer release cause message is structured, e.g., as:

IE type Information and Semantics Element/Group name Need Multireference description Signaling Connection MP Enumerated ReleaseIndication Cause (UE Requested PS Data session end, T3310 expiry, T3330expiry, T3340 expiry)In this example, the T3310, T330, and T3340 expiries correspond toexpiration of correspondingly-numbered timers, identified previously. Acause value is settable, in one implementation, as a “UE Requested PSData session end” rather than a “UE Requested idle transition” to removethe UE indication of a preference for an idle transition and provide forthe UTRAN to decide upon the state transition, although the expectedresult corresponds to that identified by the cause value. The extensionto the signaling connection release indication is preferably, but notnecessarily, a non-critical extension.

Reference is now made to FIG. 9. FIG. 9 is a flow chart of an exemplaryUE monitoring whether or not to send a signaling connection releaseindication for various domains (e.g., PS or CS). The process starts instep 910.

The UE transitions to step 912 in which it checks to see whether anabnormal condition exists. Such an abnormal condition can include, forexample, timer T3310, timer T3320, or timer T3340 expiring as describedabove. If these timers expire a certain predetermined number of times orif an explicit rejection is received based on the expiry of any of thesetimers, the UE proceeds to step 914 in which it sends a signalingconnection release indication. The SIGNALING CONNECTION RELEASEINDICATION message is appended with a signaling release indication causefield. The signaling release indication cause field includes at leastthat the signaling release indication is based on an abnormal conditionor state and one embodiment includes the specific timer that timed outto result in the abnormal condition.

Conversely, if in steps 912 the UE finds that no abnormal conditionexists, the UE proceeds to step 920 in which it checks whether furtherdata is expected at the UE. This can, as described above, include whenan email is sent and confirmation of the sending of the email isreceived back at the UE. Other examples of where the UE will determinethat no further data is expected would be known to those skilled in theart.

If in step 920 the UE determines that the data transfer is finished (orin the case of a circuit switched domain that a call is finished) the UEproceeds to step 922 in which it sends a signaling connection releaseindication in which the signaling release indication cause field hasbeen added and includes the fact that the UE requested an idletransition or simply indicate an end to the PS session.

From step 920, if the data is not finished the UE loops back andcontinues to check whether an abnormal condition exists in step 912 andwhether the data is finished in step 920.

Once the signaling connection release indication is sent in step 914 orstep 922, the process proceeds to step 930 and ends.

The UE includes functional elements, implementable, for instance, byapplications or algorithms carried out through operation of a UEmicroprocessor or by hardware implementation, that form a checker and atransition indication sender. The checker is configured to check whethera transition indication should be sent. And, a transition indicationsender is configured to send a transition indication responsive to anindication by the checker that the transition indication should be sent.The transition indication may include a transition indication causefield.

In one implementation, the network is, instead, implicitly made aware oftiming out of a timer, and the UE need not send a cause value indicatingthe timing out of the timer. That is to say, the timer starts timingupon authorization of the network. Cause codes are defined, and thecause codes are provided by the network to the UE. Such cause codes areused by the UE to initiate the timer. The network is implicitly aware ofthe reason for subsequent timing out of the timer as the cause code sentearlier by the network causes the timer to start timing. As a result,the UE need not send a cause value indicating the timing out of thetimer.

As suggested by FIG. 9 as well as the foregoing description, a cause isincludable and sent together with a transition indication (e.g. aSIGNALING CONNECTION RELEASE INDICATION) to indicate: 1.) an abnormalcondition as well as 2.) a normal condition (not an abnormal conditionsuch as for example a request for a PS data session end and/or atransition to an idle mode)). In various implementations, therefore,operations at the UE provide for the adding of the cause to thetransition indication to indicate an abnormal condition, or,alternately, to indicate a preference for a request of an idletransition or of a PS data session end, i.e., normal operation. Suchoperation, of course, also includes UE operation in which a cause isadded to the transition indication only when an indication of anabnormal condition is to be made. And, conversely, such operation alsoincludes UE operation in which a cause is added to a transitionindication only to indicate normal, non-abnormal, operations andtransactions. That is to say, with respect to FIG. 9, in suchalternative operation, if, at step 912, an abnormal condition exists,the yes branch is taken to the step 914 while, if an abnormal conditiondoes not exist, then the UE proceeds directly to the end step 930.Conversely, in the other such alternative operation, subsequent to thestart step 912 a path is taken directly to the data finished step 920.If the data is finished, the yes branch is taken to the step 920 and,thereafter, to the step 930. If the data is not finished at the step920, the no branch is taken back to the same step, i.e., step 920.

Referring to FIG. 10, when a network element receives the transitionindication in step 1010 (e.g. a signaling connection release indicationas shown), the network element examines the transition indication causefield if present in step 1014 and in step 1016 checks whether the causeis an abnormal cause or whether it is due to the UE requesting an idletransition and/or PS data session end. If, in step 1016, the signalingconnection release indication is of abnormal cause, the network nodeproceeds to step 1020 in which an alarm may be noted for performancemonitoring and alarm monitoring purposes. The key performance indicatorcan be updated appropriately.

Conversely, if in step 1016 the cause of the transition indication(e.g., signaling connection release indication) is not a result of anabnormal condition, or in other words is a result of the UE requesting aPS data session end or idle transition, the network node proceeds tostep 1030 in which no alarm is raised and the indication can be filteredfrom the performance statistics, thereby preventing the performancestatistics from being skewed. From step 1020 or step 1030 the networknode proceeds to step 1040 in which the process ends.

The reception and examination of the transition indication may result inthe initiation by the network element of packet switched data connectiontermination or alternatively to a transition into another more suitablestate, for example, CELL_FACH, CELL_PCH, URA_PCH or IDLE_MODE.

As suggested above, in some implementations, the absence of a cause in atransition indication may also be used to determine whether thetransition indication is a result of a normal or an abnormal conditionand whether an alarm must be raised. For example, if a cause is addedonly to denote normal conditions (i.e., non-abnormal such as for e.g., arequest for PS data session end and/or transition to idle mode), and thenetwork element receives a transition indication with no cause added,the network element may infer from the absence of a cause that thetransition indication is a result of an abnormal condition andoptionally raise an alarm. Conversely, in another example, if a cause isadded only to denote abnormal conditions, and the network elementreceives a transition indication with no cause, the network element mayinfer from the absence of a cause that the transition indication is aresult of a normal condition (e.g. request for PS data session endand/or transition to idle mode) and not raise an alarm.

As will be appreciated by those skilled in the art, step 1020 can beused to further distinguish between various alarm conditions. Forexample, a T3310 time out could be used to keep a first set ofstatistics and a T3330 time out could be used to keep a second set ofstatistics. Step 1020 can distinguish between the causes of the abnormalcondition, thereby allowing the network operator to track performancemore efficiently.

The network includes functional elements, implementable, for instance,by applications or algorithms carried out through operation of aprocessor or by hardware implementation, that form an examiner and analarm generator. The examiner is configured to examine a transitionindication cause field of the transition indication. The examiner checkswhether the transition indication cause field indicates an abnormalcondition. The alarm generator is configured to selectably generate analarm if examination by the examiner determines the signaling connectionrelease indication cause field indicates the abnormal condition.

In one implementation, upon reception of a signaling connection releaseindication, the UTRAN forwards the cause that is received and requests,from upper layers, for the release of the signaling connection. Theupper layers then are able to initiate the release of the signalingconnection. The IE signaling release indication cause indicates the UE'supper layer cause to trigger the RRC of the UE to send the message. Thecause is possibly the result of an abnormal upper layer procedure.Differentiation of the cause of the message is assured throughsuccessful reception of the IE.

A possible scenario includes a scenario in which, prior to confirmationby the RLC of successful delivery of the SIGNALING CONNECTION RELEASEINDICATION message, reestablishment of the transmitting side of the RLCentity on the signaling radio bearer RB2 occurs. In the event of such anoccurrence, the UE retransmits the SIGNALING CONNECTION RELEASEINDICATION message, e.g., on the uplink DCCH using AM RLC on signalingradio bearer RB2. In the event that an inter-RAT (radio accesstechnology) handover from UTRAN procedure occurs prior to confirmationby the RLC of the successful delivery of the SIGNALING CONNECTIONRELEASE INDICATION or request message, the UE aborts the signalingconnection when in the new RAT.

In a further embodiment, instead of a “signaling connection releaseindication” or request, a “data transfer complete indication” could beutilized. Functionality similar to that described in FIGS. 9 and 10above would be applicable to this data transfer complete indication.

In one embodiment, the data transfer complete indication is used by theUE to inform the UTRAN that the UE has determined that there is noon-going CS domain data transfer, and it has completed its PS datatransfer. Such a message is sent from the UE to UTRAN on the DCCH usingAM RLC, for example. An exemplary message is shown below.

10.2.x Data Transfer Complete Indication

-   -   This message is used by the UE to inform the UTRAN that the UE        has determined that there is no on-going CS domain data        transfer, and it has completed its PS data transfer.    -   RLC-SAP: AM    -   Logical channel: DCCH    -   Direction: UE→UTRAN

Data Transfer Complete Indication IE type Information and SemanticsElement/Group name Need Multi reference description Message Type MPMessage type UE Information Elements Integrity check info MP Integritycheck info 10.3.3.16

Reference is now made to FIG. 20. FIG. 20 illustrates the embodimentwithin which a transition indication or request (for e.g. a signalingconnection release indication or a data transfer complete indication) issent from the UE to the UTRAN. The process starts at step 2010 andproceeds to step 2012 in which a check is made on the UE to determinewhether the conditions at the UE are appropriate to send a transitionindication message. Such conditions are described in the presentdisclosure, for example with reference to FIG. 11 below, and couldinclude one or more applications on the UE determining that they arefinished with data exchange. Such conditions may also include waitingfor some time duration for the timer T3xx to expire if it is running.

In a further and alternative embodiment, the conditions may includeprecluding the sending of the transition indication if timer T3xx is setto infinity. As will be appreciated, T3xx could include a number ofdiscrete values, one of which represents an infinity value.

If, in step 2012, the conditions are not appropriate to send thetransition indication or request message, the process loops on itselfand continues to monitor until conditions are appropriate to send thetransition indication or request message.

Once the conditions are appropriate the process proceeds to step 2020 inwhich a transition indication is sent to the UTRAN. Exemplaryindications are shown in the tables above.

The process then proceeds to step 2022 in which a check is made todetermine whether the transition indication was successful. As would beappreciated by those skilled in the art this could mean that the UTRANhas successfully received the transition indication and has initiated astate transition. If yes, the process proceeds to step 2030 and ends.

Conversely, if it is determined in step 2022 that the transitionindication was not successful, the process proceeds to step 2024 andwaits for a time period. Such a wait could be implemented using an“inhibit duration”, e.g. T3xx, that would not allow the mobile to sendanother transition indication message before a given duration haselapsed. Alternatively, the process could limit the number of transitionindication messages within a given time period (e.g. no more than 15messages in 10 minutes). A combination of the inhibition duration andlimiting the number of messages within a given time period is alsopossible.

The duration could be predetermined, such as a value defined in thestandards, could be set by a network element, for example, as part of aRRC connection request, a RRC connection setup message, a RRC connectionrelease, a radio bearer set up, a system information broadcast message,a system information block message, an ACTIVE SET UPDATE, a CELL UPDATECONFIRM, UTRAN Mobility Information Message, a Handover to UTRANCommand, a Physical Channel Reconfiguration Message, a Radio BearerReconfiguration Message, a Radio Bearer Release Message, a TransportChannel Reconfiguration Message, or any request, configuration orreconfiguration message. Further, the duration could be set based on aparameter within the transition indication message. Thus, the durationcould be longer if the UE is requesting a transition to Cell_PCH ratherthan Idle.

The signaling or sending of the duration by a network element could takethe form of an information element. As used herein, signaling or sendingcould include directly sending the information to a UE, or broadcastingthe information. Similarly, receiving at the UE could include directreception or reading of a broadcast channel. One exemplary informationelement includes:

Inhibit Transition Indication Information Element/ Type and SemanticsGroup name Need Multi reference description Inhibit Transition MPEnumerated(T3xx, Indication 1 spare value)

The values of T3xx, in one embodiment are defined as:

T3xx Definition Information Element/ Type and Semantics Group name NeedMulti reference description T3xx MD Enumerated Value in seconds. Two (0,30, 60, spare values are needed. 90, 120, The use of 0 seconds infinity)indicates no need to apply the inhibit timer, and may be sent tooverride a previous non 0 setting. The use of infinity indicates neversend the Transition Indication Message.

In one embodiment T3xx can be included in the existing UMTS InformationElement “UE Timers and Constants in connected mode”. This can thereforebe broadcast in a cell by inclusion in System Information Block Type 1.In an alternative embodiment, the timer value could also be signaledusing other system information messages, such as SIB3 or SIB4, or eitheralternatively or additionally could be signaled with a dedicated UTRANmobility information message.

As indicated in the Table above, the T3xx value can vary between setvalues and include a zero value or an infinity value. The zero value isused to indicate that no inhibition needs to occur. The infinity valueindicates that a Transition Indication Message should never be sent.

In one mobility embodiment, the UE resets the T3xx value whenever a newnetwork or cell is transitioned to. In this example, the value is set toinfinity. This ensures that if a transitioning messages or Radio BearerMessages do not contain an inhibit timer value, then by default the UEis not to send the Transition Indication Message. Thus, for example, ifthe transition or Radio Bearer Messages do not contain an “InhibitTransition Indication”, the value of the timer is set to infinity andotherwise the value of the timer received in the indication replaces anypreviously stored value.

In another alternative embodiment the values of T3xx, are defined asfollows. The inclusion of the timer T3xx is optional thereby ensuringthat if not included, the UE need not have to support configuring orusing this timer:

An alternative T3xx Definition Information Element/ Type and SemanticsGroup name Need Multi reference description T3xx OP Enumerated Value inseconds. (0, 5, 10, The use of 0 seconds 20, 30, 60, indicates no needto 90, 120) apply the inhibit timer, and may be sent to override aprevious non 0 setting.

The reception of the inhibit timer in a cell is thus an indication tothe UE that the cell recognizes the use of the transition indicationmessage. The UE may determine, if initiated by the RRC or higher layersdue to a determination of no more PS domain data for a prolongedduration, to signal a transition indication using a cause value. Whenthe network receives a transition indication message (of whatever form,as captured in this document) with this cause value it may determine tosignal to the UE a state transition change to a more battery efficientRRC State.

Whereas in an alternative embodiment, when the inhibit timer is notreceived or read in a cell, the UE can determine that the cause forsending the transition indication message, is not supported by theUTRAN. In this case the UE can determine to not configure a value forT3xx and also not to use the T3xx in relation to sending or inhibitingthe sending of the transition indication message.

If the UE determines that the inhibit timer is omitted, then it may omitto include the cause value from the transition indication message andjust send the transition indication message, based on higher layerdetermining that it has no more PS data to transmit.

In an alternative embodiment, the UE, on determining that the inhibittimer is omitted, the UE shall not initiate a transition indicationbased on higher layer determining that it has no more PS data totransmit.

In one embodiment of this described behavior, the transition indicationmessage is the SIGNALING CONNECTION RELEASE INDICATION message.

In a first alternative embodiment, the reception of the inhibit timer ina cell is thus an indication that the cell recognizes the use of thetransition indication messages. Where the sending of this message ispermitted when the T3xx is not set to infinity value, then when thenetwork receives a transition indication it may determine to signal tothe UE a state transition to a more battery efficient RRC State (e.g.,CELL_FACH, CELL_PCH, URA_PCH or IDLE_MODE).

In a particular example utilizing 3GPP TSG-RAN2 25.331 standard, thefollowing is added to the sections identified below:

Inhibit Transition Indication Inhibit Transition OP Inhibit TransitionIndication Indication 10.3.3.14b

This is added to sections:

10.2.48.8.6 System Information Block Type 3;

10.2.48.8.7 System Information Block Type 4;

10.2.1 Active Set Update;

10.2.8 Cell Update Confirm;

10.2.16a Handover to UTRAN Command;

10.2.22 Physical Channel Reconfiguration;

10.2.27 Radio Bearer Reconfiguration;

10.2.30 Radio Bearer Release;

10.2.33 Radio Bearer Setup;

10.2.40 RRC Connection Setup;

10.2.50 Transport Channel Reconfiguration;

The messages described above, besides messages 10.2.48.8.6 SystemInformation Block Type 3 and 10.2.48.8.7 System Information Block Type4, are all examples of mobility information messages.

The above covers connections and system operations, as well astransitions between various cells, ensuring that a UE has an inhibittimer value if that cell supports the transition indication message. Forexample, the Handover to UTRAN Command ensures that a transition fromanother Radio Access Technology such as a second generation network to athird generation network will provide an inhibit timer value ifsupported by the third generation network's target cell.

In particular referring to FIG. 21, a transition between cells hasoccurred as a precondition or a during other operation of the UE, asshown by reference numeral 2110 as ‘Start’. The process proceeds toblock 2112 in which a configuration message is received. This can be anyof the messages identified above, and includes both mobility andnon-mobility messages. The process then proceeds to block 2114 in whicha check is made to see whether the configuration message includes aninhibit timer value.

If not, the process proceeds to block 2120 in which the inhibit timervalue is set to infinity. Conversely, from block 2114 the processproceeds to block 2130 if it is determined that the configurationmessage does include an inhibit timer value. In block 2130 the inhibittimer value is stored on the UE, replacing the previous value for theinhibit timer. The process then proceeds to block 2140 and ends. As willbe appreciated, in one embodiment the process of FIG. 21 is invokedwhenever a change in network or cell occurs, or whenever a transitionindication needs to be sent.

Once the process has waited for a predetermined time in step 2024 theprocess proceeds back to step 2012 to determine whether the conditionsfor sending a transition indication still exist. If yes, the processloops back to step 2020 and 2022.

Based on the above, the inhibit timer value may be provided in variousembodiments. In a first embodiment, it can be provided only using an RRCConnection Setup Message to convey an inhibit timer value.

In a second embodiment, system information can be used to convey theinhibit timer value.

In a third embodiment the RRC Connection Setup and System InformationMessages can both be utilized to send the inhibit timer value to ensurethat UEs in idle mode and Cell_PCH/Cell_FACH and DCH states have thelatest information.

In a fourth embodiment the inhibit timer value can be sent as in thethird embodiment, with the addition of sending an inhibit timer value ina Radio Bearer Setup so that when a PDP context is established having noRadio Bearer, when a Radio Bearer is subsequently established to send adata message the inhibit timer value can be conveyed at that time.

In a fifth embodiment the fourth embodiment can be combined with allmobility related messages as described above and includingreconfiguration, cell update confirmation and a Handover to UTRANcommand to convey the inhibit timer value.

In the first to fourth embodiments, during mobility the UE maintains itscurrently stored inhibit timer value. As indicated above, in some caseswhere the inhibit timer is set to infinity this may mean that the UEmust wait for network timers to expire and for the network to move theUE to an RRC state where it can receive or determine a new value for theinhibit timer. In other cases where the inhibit timer is some valueother than infinity before the handover, this other value is continuedto be used until the UE is able to update the timer value to thatindicated in the new cell.

For the fifth embodiment, the process FIG. 21 is utilized to ensure thatthe inhibit timer value is updated during mobility, and that transitionindication messages are not sent unnecessarily from a UE.

An exception may occur on RLC re-establishment or inter-RAT change. If are-establishment of the transmitting side of the RLC entity occursbefore the successful delivery of the transition indication message hasbeen confirmed by the RLC, in one embodiment the UE retransmits thetransition indication message on the uplink DCCH using AM RLC.

In one embodiment, if an inter-RAT handover from UTRAN procedure occursbefore the successful delivery of the transition indication message hasbeen confirmed by the RLC the UE aborts the signaling connection whilein the new RAT.

On the network side, the process is handled similarly to that describedwith reference to FIG. 18 below.

Referring again to FIG. 1, in some cases it may be more desirable to bein the connected mode 120 in a state such as URA_PCH state 128 than inidle mode 110. For example, if the latency for connection to theCELL_DCH state 122 or the CELL_FACH state 124 in connected mode 120 isrequired to be lower, it is preferable to be in a connected mode 120 PCHstate. There are a number of ways of accomplishing this such as, forexample, by amending standards to allow for the UE to request the UTRANmove it to a specific state (e.g., in this case the URA_PCH state 128).

Alternatively, the connection manager may take into account otherfactors such as what state the RRC connection is currently in. If, forexample, the RRC connection is in the URA_PCH state it may decide thatit is unnecessary to move to idle mode 110 and thus no signalingconnection release procedure is initiated.

In a further alternative, the network element (e.g. the UTRAN) mayitself take into account other factors such as what state the RRCconnection is currently in and if, for example, the RRC connection is inthe URA_PCH state it may decide that it is unnecessary to move to idlemode 110 and instead simply transition the UE into a more suitable stateinstead of releasing the connection.

Reference is made to FIG. 4. FIG. 4A shows a current UMTS implementationaccording to the infrastructure “four” example above. As illustrated inFIG. 4, time is across the horizontal axes.

The UE starts in RRC idle state 110 and based on local or mobilegenerated data needing to be transmitted or a page received from theUTRAN, starts to establish an RRC connection.

As illustrated in FIG. 4A, RRC connection setup 310 occurs first, andthe RRC state is in a connecting state 410 during this time.

Next, signaling connections setup 312, ciphering and integrity setup314, and radio bearer setup 316 occurs. The RRC state is CELL_DCH state122 during these procedures. As illustrated in FIG. 4A, the elapsed timefor moving from RRC idle to the time that the radio bearer is setup isapproximately two seconds in this example.

Data is next exchanged. In the example of FIG. 4A, this is achieved inabout two to four seconds and is illustrated by step 420.

After data is exchanged in step 420, no data is being exchanged exceptfor intermittent RLC signaling PDU as required and thus the radioresource is reconfigured by the network to move into a lower data rateDCH configuration after approximately ten seconds. This is illustratedin steps 422 and 424.

In the lower data rate DCH configuration, nothing is received forseventeen seconds, at which point the RRC connection is released by thenetwork in step 428.

Once the RRC connection release is initiated in step 428, the RRC stateproceeds to a disconnecting state 430 for approximately fortymilliseconds, after which the UE is in a RRC idle state 110.

Also illustrated in FIG. 4A, the UE current consumption is illustratedfor the period in which the RRC is in CELL_DCH state 122. As seen, thecurrent consumption is approximately 200 to 300 milliamps for the entireduration of the CELL_DCH state. During disconnect and idle, about 3milliamps are utilized, assuming a DRX cycle of 1.28 seconds. However,the 35 seconds of current consumption at 200 to 300 milliamps isdraining on the battery.

Reference is now made to FIG. 4B. FIG. 4B utilizes the same exemplaryinfrastructure “four” from above, only now implementing the signalingconnection release

As illustrated in FIG. 4B, the same setup steps 310, 312, 314 and 316occur and this takes the same amount of time when moving between RRCidle state 110 and RRC CELL_DCH state 122.

Further, the RRC data PDU exchange for the exemplary email at step 420of FIG. 4A is also done at FIG. 4B and this takes approximately two tofour seconds.

The UE in the example of FIG. 4B has an application specific inactivitytimeout, which in the example of FIG. 4B is two seconds and isillustrated by step 440. After the connection manager has determinedthat there is inactivity for the specific amount of time, the UE sends atransition indication, which in this case is a signaling connectionrelease indication in step 442 and in step 448, the network proceeds,based on the receipt of the indication and on a radio resource profilefor the UE, to release the RRC connection.

As illustrated in FIG. 4B, the current consumption during the CELL_DCHstep 122 is still about 200 to 300 milliamps. However, the connectiontime is only about eight seconds. As will be appreciated by thoseskilled in the art, the considerably shorter amount of time that themobile stays in the cell DCH state 122 results in significant batterysavings for UE device.

Reference is now made to FIG. 5. FIG. 5 shows a second example using theinfrastructure indicated above as Infrastructure “three”. As with FIGS.4A and 4B, a connection setup occurs which takes approximately twoseconds. This requires the RRC connection setup 310, the signalingconnection setup 312, the ciphering and integrity setup 314 and theradio bearer setup 316.

During this setup, the UE moves from RRC idle mode 110 to a CELL_DCHstate 122 with a RRC state connecting step 410 in between.

As with FIG. 4A, in FIG. 5A RLC data PDU exchange occurs at step 420,and in the example of FIG. 5A takes two to four seconds.

According to the infrastructure three, RLC signaling PDU exchangereceives no data and thus is idle for a period of five seconds in step422, except for intermittent RLC signaling PDU as required, at whichpoint the radio resource reconfigures the UE to move into a CELL_FACHstate 124 from CELL_DCH state 122. This is done in step 450.

In the CELL_FACH state 124, the RLC signaling PDU exchange finds thatthere is no data except for intermittent RLC signaling PDU as requiredfor a predetermined amount of time, in this case thirty seconds, atwhich point a RRC connection release by network is performed in step428.

As seen in FIG. 5A, this moves the RRC state to idle mode 110.

As further seen in FIG. 5A, the current consumption during the DCH modeis between 200 and 300 milliamps. When moving into CELL_FACH state 124the current consumption lowers to approximately 120 to 180 milliamps.After the RRC connector is released and the RRC moves into idle mode 110the power consumption is approximately 3 milliamps.

The UTRA RRC Connected Mode state being CELL_DCH state 122 or CELL_FACHstate 124 lasts for approximately forty seconds in the example of FIG.5A.

Reference is now made to FIG. 5B. FIG. 5B illustrates the sameinfrastructure “three” as FIG. 5A with the same connection time of abouttwo seconds to get the RRC connection setup 310, signaling connectionsetup 312, ciphering integrity setup 314 and radio bearer setup 316.Further, RLC data PDU exchange 420 take approximately two to fourseconds.

As with FIG. 4B, a UE application detects a specific inactivity timeoutin step 440, at which point the transition indication (e.g. signalingconnection release indication 442) is sent by the UE and as aconsequence, the network releases the RRC connection in step 448.

As can be seen further in FIG. 5B, the RRC starts in a idle mode 110,moves to a CELL_DCH state 122 without proceeding into the CELL_FACHstate.

As will be seen further in FIG. 5B, current consumption is approximately200 to 300 milliamps in the time that the RRC stage is in CELL_DCH state122 which according to the example of FIG. 5 is approximately eightseconds.

Therefore, a comparison between FIGS. 4A and 4B, and FIGS. 5A and 5Bshows that a significant amount of current consumption is eliminated,thereby extending the battery life of the UE. As will be appreciated bythose skilled in the art, the above can further be used in the contextof current 3GPP specs.

Reference is now made to FIG. 6. FIG. 6 illustrates a protocol stack fora UMTS network.

As seen in FIG. 6, the UMTS includes a CS control plane 610, PS controlplane 611, and PS user plane 630.

Within these three planes, a non-access stratum (NAS) portion 614 and anaccess stratum portion 616 exist.

NAS portion 614 in CS control plane 610 includes a call control (CC)618, supplementary services (SS) 620, and short message service (SMS)622.

NAS portion 614 in PS control plane 611 includes both mobilitymanagement (MM) and GPRS mobility management (GMM) 626. It furtherincludes session management/radio access bearer management SM/RABM 624and GSMS 628.

CC 618 provides for call management signaling for circuit switchedservices. The session management portion of SM/RABM 624 provides for PDPcontext activation, deactivation and modification. SM/RABM 624 alsoprovides for quality of service negotiation.

The main function of the RABM portion of the SM/RABM 624 is to connect aPDP context to a Radio Access Bearer. Thus SM/RABM 624 is responsiblefor the setup, modification and release of radio resources.

CS control plane 610 and PS control plane 611, in the access stratum 616sit on radio resource control (RRC) 617.

NAS portion 614 in PS user plane 630 includes an application layer 638,TCP/UDP layer 636, and PDP layer 634. PDP layer 634 can, for example,include Internet Protocol (IP).

Access Stratum 616, in PS user plane 630 includes packet dataconvergence protocol (PDCP) 632. PDCP 632 is designed to make the WCDMAprotocol suitable to carry TCP/IP protocol between UE and RNC (as seenin FIG. 8), and is optionally for IP traffic stream protocol headercompression and decompression.

The UMTS Radio Link Control (RLC) 640 and Medium Access Control (MAC)layers 650 form the data link sub-layers of the UMTS radio interface andreside on the RNC node and the User Equipment.

The Layer 1 (L1) UMTS layer (physical layer 660) is below the RLC/MAClayers 640 and 650. This layer is the physical layer for communications.

While the above can be implemented on a variety of mobile or wirelessdevices, an example of one mobile device is outlined below with respectto FIG. 7. Reference is now made to FIG. 7.

UE 700 is preferably a two-way wireless communication device having atleast voice and data communication capabilities. UE 700 preferably hasthe capability to communicate with other computer systems on theInternet. Depending on the exact functionality provided, the wirelessdevice may be referred to as a data messaging device, a two-way pager, awireless e-mail device, a cellular telephone with data messagingcapabilities, a wireless Internet appliance, or a data communicationdevice, as examples.

Where UE 700 is enabled for two-way communication, it will incorporate acommunication subsystem 711, including both a receiver 712 and atransmitter 714, as well as associated components such as one or more,preferably embedded or internal, antenna elements 716 and 718, localoscillators (LOs) 713, and a processing module such as a digital signalprocessor (DSP) 720. As will be apparent to those skilled in the fieldof communications, the particular design of the communication subsystem711 will be dependent upon the communication network in which the deviceis intended to operate. For example, UE 700 may include a communicationsubsystem 711 designed to operate within the GPRS network or UMTSnetwork.

Network access requirements will also vary depending upon the type ofnetwork 719. For example, in UMTS and GPRS networks, network access isassociated with a subscriber or user of UE 700. For example, a GPRSmobile device therefore requires a subscriber identity module (SIM) cardin order to operate on a GPRS network. In UMTS a USIM or SIM module isrequired. In CDMA, a RUIM card or module is required. These will bereferred to as a UIM interface herein. Without a valid UIM interface, amobile device may not be fully functional. Local or non-networkcommunication functions, as well as legally required functions (if any)such as emergency calling, may be available, but mobile device 700 willbe unable to carry out any other functions involving communications overthe network 700. The UIM interface 744 is normally similar to acard-slot into which a card can be inserted and ejected like a disketteor PCMCIA card. The UIM card can have approximately 64K of memory andhold many key configuration 751, and other information 753 such asidentification, and subscriber related information.

When required network registration or activation procedures have beencompleted, UE 700 may send and receive communication signals over thenetwork 719. Signals received by antenna 716 through communicationnetwork 719 are input to receiver 712, which may perform such commonreceiver functions as signal amplification, frequency down conversion,filtering, channel selection and the like, and in the example systemshown in FIG. 7, analog to digital (ND) conversion. ND conversion of areceived signal allows more complex communication functions such asdemodulation and decoding to be performed in the DSP 720. In a similarmanner, signals to be transmitted are processed, including modulationand encoding for example, by DSP 720 and input to transmitter 714 fordigital to analog conversion, frequency up conversion, filtering,amplification and transmission over the communication network 719 viaantenna 718. DSP 720 not only processes communication signals, but alsoprovides for receiver and transmitter control. For example, the gainsapplied to communication signals in receiver 712 and transmitter 714 maybe adaptively controlled through automatic gain control algorithmsimplemented in DSP 720.

Network 719 may further communicate with multiple systems, including aserver 760 and other elements (not shown). For example, network 719 maycommunicate with, both an enterprise system and a web client system inorder to accommodate various clients with various service levels.

UE 700 preferably includes a microprocessor 738, which controls theoverall operation of the device. Communication functions, including atleast data communications, are performed through communication subsystem711. Microprocessor 738 also interacts with further device subsystemssuch as the display 722, flash memory 724, random access memory (RAM)726, auxiliary input/output (I/O) subsystems 728, serial port 730,keyboard 732, speaker 734, microphone 736, a short-range communicationssubsystem 740 and any other device subsystems generally designated as742.

Some of the subsystems shown in FIG. 7 perform communication-relatedfunctions, whereas other subsystems may provide “resident” or on-devicefunctions. Notably, some subsystems, such as keyboard 732 and display722, for example, may be used for both communication-related functions,such as entering a text message for transmission over a communicationnetwork, and device-resident functions such as a calculator or tasklist.

Operating system software used by the microprocessor 738 is preferablystored in a persistent store such as flash memory 724, which may insteadbe a read-only memory (ROM) or similar storage element (not shown).Those skilled in the art will appreciate that the operating system,specific device applications, or parts thereof, may be temporarilyloaded into a volatile memory such as RAM 726. Received communicationsignals may also be stored in RAM 726. Further, a unique identifier isalso preferably stored in read-only memory.

As shown, flash memory 724 can be segregated into different areas forboth computer programs 758 and program data storage 750, 752, 754 and756. These different storage types indicate that each program canallocate a portion of flash memory 724 for their own data storagerequirements. Microprocessor 738, in addition to its operating systemfunctions, preferably enables execution of software applications on themobile device. A predetermined set of applications that control basicoperations, including at least data and voice communication applicationsfor example, will normally be installed on UE 700 during manufacturing.A preferred software application may be a personal information manager(PIM) application having the ability to organize and manage data itemsrelating to the user of the mobile device such as, but not limited to,e-mail, calendar events, voice mails, appointments, and task items.Naturally, one or more memory stores would be available on the mobiledevice to facilitate storage of PIM data items. Such PIM applicationwould preferably have the ability to send and receive data items, viathe wireless network 719. In a preferred embodiment, the PIM data itemsare seamlessly integrated, synchronized and updated, via the wirelessnetwork 719, with the mobile device user's corresponding data itemsstored or associated with a host computer system. Further applicationsmay also be loaded onto the mobile device 700 through the network 719,an auxiliary I/O subsystem 728, serial port 730, short-rangecommunications subsystem 740 or any other suitable subsystem 742, andinstalled by a user in the RAM 726 or preferably a non-volatile store(not shown) for execution by the microprocessor 738. Such flexibility inapplication installation increases the functionality of the device andmay provide enhanced on-device functions, communication-relatedfunctions, or both. For example, secure communication applications mayenable electronic commerce functions and other such financialtransactions to be performed using the UE 700. These applications willhowever, according to the above, in many cases need to be approved by acarrier.

In a data communication mode, a received signal such as a text messageor web page download will be processed by the communication subsystem711 and input to the microprocessor 738, which preferably furtherprocesses the received signal for output to the display 722, oralternatively to an auxiliary I/O device 728. A user of UE 700 may alsocompose data items such as email messages for example, using thekeyboard 732, which is preferably a complete alphanumeric keyboard ortelephone-type keypad, in conjunction with the display 722 and possiblyan auxiliary I/O device 728. Such composed items may then be transmittedover a communication network through the communication subsystem 711.

For voice communications, overall operation of UE 700 is similar, exceptthat received signals would preferably be output to a speaker 734 andsignals for transmission would be generated by a microphone 736.Alternative voice or audio I/O subsystems, such as a voice messagerecording subsystem, may also be implemented on UE 700. Although voiceor audio signal output is preferably accomplished primarily through thespeaker 734, display 722 may also be used to provide an indication ofthe identity of a calling party, the duration of a voice call, or othervoice call related information for example.

Serial port 730 in FIG. 7 would normally be implemented in a personaldigital assistant (PDA)-type mobile device for which synchronizationwith a user's desktop computer (not shown) may be desirable. Such a port730 would enable a user to set preferences through an external device orsoftware application and would extend the capabilities of mobile device700 by providing for information or software downloads to UE 700 otherthan through a wireless communication network. The alternate downloadpath may for example be used to load an encryption key onto the devicethrough a direct and thus reliable and trusted connection to therebyenable secure device communication.

Alternatively, serial port 730 could be used for other communications,and could include as a universal serial bus (USB) port. An interface isassociated with serial port 730.

Other communications subsystems 740, such as a short-rangecommunications subsystem, is a further optional component which mayprovide for communication between UE 700 and different systems ordevices, which need not necessarily be similar devices. For example, thesubsystem 740 may include an infrared device and associated circuits andcomponents or a Bluetooth™ communication module to provide forcommunication with similarly enabled systems and devices.

Reference is now made to FIG. 8. FIG. 8 is a block diagram of acommunication system 800 that includes a UE 802 which communicatesthrough the wireless communication network.

UE 802 communicates wirelessly with one or multiple Node Bs 806. EachNode B 806 is responsible for air interface processing and some radioresource management functions. Node B 806 provides functionality similarto a Base Transceiver Station in a GSM/GPRS network.

The wireless link shown in communication system 800 of FIG. 8 representsone or more different channels, typically different radio frequency (RF)channels, and associated protocols used between the wireless network andUE 802. A Uu air interface 804 is used between UE 802 and Node B 806.

An RF channel is a limited resource that must be conserved, typicallydue to limits in overall bandwidth and a limited battery power of UE802. Those skilled in art will appreciate that a wireless network inactual practice may include hundreds of cells depending upon desiredoverall expanse of network coverage. All pertinent components may beconnected by multiple switches and routers (not shown), controlled bymultiple network controllers.

Each Node B 806 communicates with a radio network controller (RNC) 810.The RNC 810 is responsible for control of the radio resources in itsarea. One RNC 810 controls multiple Node Bs 806.

The RNC 810 in UMTS networks provides functions equivalent to the BaseStation Controller (BSC) functions in GSM/GPRS networks. However, an RNC810 includes more intelligence, including, for example, autonomoushandovers management without involving MSCs and SGSNs.

The interface used between Node B 806 and RNC 810 is a lub interface808. An NBAP (Node B application part) signaling protocol is primarilyused, as defined in 3GPP TS 25.433 V3.11.0 (2002-09) and 3GPP TS 25.433V5.7.0 (2004-01).

Universal Terrestrial Radio Access Network (UTRAN) 820 comprises the RNC810, Node B 806 and the Uu air interface 804.

Circuit switched traffic is routed to Mobile Switching Centre (MSC) 830.MSC 830 is the computer that places the calls, and takes and receivesdata from the subscriber or from PSTN (not shown).

Traffic between RNC 810 and MSC 830 uses the Iu-CS interface 828. Iu-CSinterface 828 is the circuit-switched connection for carrying(typically) voice traffic and signaling between UTRAN 820 and the corevoice network. The main signaling protocol used is RANAP (Radio AccessNetwork Application Part). The RANAP protocol is used in UMTS signalingbetween the Core Network 821, which can be a MSC 830 or SGSN 850(defined in more detail below) and UTRAN 820. RANAP protocol is definedin 3GPP TS 25.413 V3.11.1 (2002-09) and TS 25.413 V5.7.0 (2004-01).

For all UEs 802 registered with a network operator, permanent data (suchas UE 802 user's profile) as well as temporary data (such as UE's 802current location) are stored in a home location registry (HLR) 838. Incase of a voice call to UE 802, HLR 838 is queried to determine thecurrent location of UE 802. A Visitor Location Register (VLR) 836 of MSC830 is responsible for a group of location areas and stores the data ofthose mobile stations that are currently in its area of responsibility.This includes parts of the permanent mobile station data that have beentransmitted from HLR 838 to the VLR 836 for faster access. However, theVLR 836 of MSC 830 may also assign and store local data, such astemporary identifications. UE 802 is also authenticated on system accessby HLR 838.

Packet data is routed through Service GPRS Support Node (SGSN) 850. SGSN850 is the gateway between the RNC and the core network in a GPRS/UMTSnetwork and is responsible for the delivery of data packets from and tothe UEs within its geographical service area. Iu-PS interface 848 isused between the RNC 810 and SGSN 850, and is the packet-switchedconnection for carrying (typically) data traffic and signaling betweenthe UTRAN 820 and the core data network. The main signaling protocolused is RANAP (described above).

The SGSN 850 communicates with the Gateway GPRS Support Node (GGSN) 860.GGSN 860 is the interface between the UMTS/GPRS network and othernetworks such as the Internet or private networks. GGSN 860 is connectedto a public data network PDN 870 over a Gi interface.

Those skilled in art will appreciate that wireless network may beconnected to other systems, possibly including other networks, notexplicitly shown in FIG. 8. A network will normally be transmitting atvery least some sort of paging and system information on an ongoingbasis, even if there is no actual packet data exchanged. Although thenetwork consists of many parts, these parts all work together to resultin certain behaviours at the wireless link.

FIG. 11 illustrates a representation, shown generally at 1102,representative of operation of the UE pursuant to multiple, concurrentpacket data communication service sessions. Here, two packet dataservices, each associated with a particular PDP context designated asPDP₁ and PDP₂ are concurrently active. The plot 1104 represents the PDPcontext activated to the first packet data service, and the plot 1106represents the radio resource allocated to the first packet dataservice. And, the plot 1108 represents the PDP context activated to thesecond packet data service, and the plot 1112 represents the radioresource allocated to the second packet data service. The UE requestsradio access bearer allocation by way of a service request, indicated bythe segments 1114. And, the UE also requests radio bearer servicerelease, indicated by the segments 1116 pursuant to an embodiment of thepresent disclosure. The service requests and service releases for theseparate services are independent of one another, that is to say, aregenerated independently. In the exemplary illustration of FIG. 11, thePDP context and the radio resource for the associated PDP context areassigned at substantially concurrent times. And, the radio resourcerelease is granted upon request by the UE, as shown, or when the RNC(Radio Network Controller) decides to release the radio resource.

Responsive to a radio resource release request, or other decision torelease the radio resource, the network selectably tears down the radioresource associated with the packet data service. Radio release requestsare made on a radio access bearer-by-radio access bearer basis and noton an entire signaling connection basis, thereby permitting improvedgranularity control of resource allocation.

In the exemplary implementation, a single packet data service is furtherformable as a primary service and one or more secondary services, suchas indicated by the designations 1118 and 1122. The radio resourcerelease is further permitting of identifying which of one or moreprimary and secondary services whose radio resource allocations are nolonger needed, or otherwise are desired to be released. Efficient radioresource allocation is thereby provided. In addition, optimalutilization of the processor on the UE is provided since the processorpower that would have been allocated to unnecessary processing can nowbe better utilized for other purposes.

FIG. 12 illustrates parts of the communication system 800, namely, theUE 802 and the radio network controller (RNC)/SGSN 810/850 that operatepursuant to an embodiment of the present disclosure pertaining to themultiple, contiguous packet data service sessions. The UE includesapparatus 1126 and the RNC/SGSN includes apparatus 1128 of an embodimentof the present disclosure. The elements forming the apparatus 1126 and1128 are functionally represented, implementable in any desired manner,including by algorithms executable by processing circuitry as well ashardware or firmware implementations. The elements of the apparatus1128, while represented to be embodied at the RNC/SGSN, are, in otherimplementations, formed elsewhere at other network locations, ordistributed across more than one network location.

The apparatus 1126 includes a detector 1132 and a transition indicationsender 1134. In one exemplary implementation, the elements 1132 and 1134are embodied at a session management layer, e.g., the Non-Access Stratum(NAS) layer defined in UMTS, of the UE.

In another exemplary implementation, the elements are embodied at anAccess Stratum (AS) sublayer. When implemented at the AS sublayer, theelements are implemented as part of a connection manager, shown at 1136.When implemented in this manner, the elements need not be aware of thePDP context behavior or of the application layer behavior.

The detector detects when a determination is made to send a transitionindication associated with a packet communication service. Thedetermination is made, e.g., at an application layer, or other logicallayer, and provided to the session management layer and the detectorembodied thereat. Indications of detections made by the detector areprovided to the radio resource release indication sender. The sendergenerates and causes the UE to send a transition indication that formsthe service release request 1116, shown in FIG. 11.

In a further implementation, the transition indication includes a causefield containing a cause, such as any of the aforementioned causesdescribed here and above, as appropriate or the cause field identifies apreferred state into which the UE prefers the network to cause the UE tobe transitioned.

The apparatus 1128 embodied at the network includes an examiner 1142 anda grantor 1144. The examiner examines the transition indication, whenreceived thereat. And, the transition grantor 1144 operates selectablyto transition the UE as requested in the transition indication.

In an implementation in which the signaling is performed at a radioresource control (RRC) layer, the radio network controller (RNC), ratherthan the SGSN performs the examination and transitioning of the UE. And,correspondingly, the apparatus embodied at the UE is formed at the RRClayer, or the apparatus otherwise causes the generated indication to besent at the RRC level.

In an exemplary control flow, a higher layer informs the NAS/RRC layer,as appropriate, that the radio resource is allocated to a particular PDPcontext is no longer required. An RRC-layer indication message is sentto the network. The message includes an RAB ID or RB ID that, e.g.,identifies the packet data service, to the radio network controller.And, in response, operation of the radio network controller triggers aprocedure to resolve to end the radio resource release, radio resourcereconfiguration, or radio resource control (RRC) connection releasemessage to be returned to the UE. The RNC procedure is, e.g., similar,or equivalent to, the procedure set forth in 3GPP document TS 23.060,Section 9.2.5. The RAB ID is, e.g., advantageously utilized as the ID isthe same as the Network Service Access Point Identifier (NSAPI) whichidentifies the associated PDP context, and application layers aregenerally aware of the NSAPI.

In a specific example, a radio resource release indication formed at, orotherwise provided to the RRC layer, and sent at the RRC layer isrepresented, together with associated information, below. The indicationwhen embodied at the RRC layer is also referred to as, e.g., a radioresource release indication.

IE type Information and Semantics Element/Group name Need Multireference description Message Type MP Message type UE InformationElements Integrity check info CH Integrity check info RAB InformationRAB List for release MP 1 to indication maxRABIDs >RAB ID for release MPRAB ID indication Preferred RRC state OP RRC state

FIG. 13 illustrates a message sequence diagram, shown generally at 1137,representing exemplary signaling generated pursuant to release of radioresources associated with a PDP context, such as that shown graphicallyin part of the graphical representation shown in FIG. 11. Release isinitiated either by the UE or at the RNC, or other UTRAN entity. Wheninitiated at the UE, e.g., the UE sends a radio resource releaseindication to the UTRAN.

Upon initiation, a radio access bearer (RAB) release request isgenerated, and sent, indicated by the segment 1138 by the RNC/UTRAN anddelivered to the SGSN. In response, an RAB assignment request isreturned, indicated by the segment 1140, to the RNC/UTRAN. And, then, asindicated by the segment 1142, the radio resources extending between theUE 802 and the UTRAN are released. A response is then sent, as indicatedby segment 1144.

FIG. 14 illustrates a message sequence diagram shown generally at 1147,similar to the message sequence diagram shown in FIG. 13, but here inwhich resources of a final PDP context are released. Upon initiation,the RNC generates an IU release request 1150 is communicated to the SGSNand responsive thereto, the SGSN returns an lu release command,indicated by the segment 1152. Thereafter, and as indicated by thesegments 1154, the radio bearer formed between the UE and the UTRAN isreleased. And, as indicated by the segment 1156, the RNC/UTRAN returnsan lu release complete to the SGSN.

FIG. 15 illustrates a method flow diagram, shown generally at 1162,representative of the process of an embodiment of the present disclosureto release radio resources allocated pursuant to a PDP context.

After start of the process, indicated by the block 1164, a determinationis made, indicated by the decision block 1166 as to whether a radioresource release indication has been received. If not, the no branch istaken to the end block 1168.

If, conversely, a radio access bearer release has been requested, theyes branch is taken to the decision block 1172. At the decision block1172, a determination is made as to whether the radio access bearer thatis to be released is the final radio access bearer to be released. Ifnot, the no branch is taken to the block 1178, and the preferred stateis set. Then radio access bearer release procedures are performed, suchas that shown in FIG. 13 or such as that described in 3GPP documentSection 23.060, subclause 9.2.5.1.1.

Conversely, if a determination is made at the decision block 1172 thatthe RAB is the last to be released, the yes branch is taken to the block1186, an IU release procedure, such as that shown in FIG. 14 or such asthat described in 3GPP document section 23.060, subclause 9.2.5.1.2 isperformed.

FIG. 16 illustrates a method flow diagram, shown generally at 1192,representative of the process of an embodiment of the present disclosureto release radio resources allocated pursuant to a PDP context.

After start of the process, indicated by the block 1194, a determinationis made, indicated by the decision block 1196 as to whether there is anRAB (Radio Access Bearer) to release. If not, the no branch is taken tothe end block 1198.

If, conversely, a radio access bearer release has been requested, theyes branch is taken to the decision block 1202. At the decision block1202, a determination is made as to whether the radio access bearer thatis to be released is the final radio access bearer to be released. Ifnot, the no branch is taken to the block 1204, where the RAB list isset, block 1206 where the preferred state is set, and block 1208 whereradio access bearer release procedures are performed, such as that shownin FIG. 13 or such as that described in 3GPP document Section 23.060,subclause 9.2.5.1.1.

Conversely, if a determination is made at the decision block 1202 thatthe RAB is the last to be released, the yes branch is taken to the block1212, and the domain is set to PS (Packet Switched). Then, as indicatedby block 1214, a release cause is set. And, as indicated by the block1216, a SIGNALING CONNECTION RELEASE INDICATION is sent on a DCCH. An IUrelease procedure, such as that shown in FIG. 14 or such as thatdescribed in 3GPP document section 23.060, subclause 9.2.5.1.2 isperformed.

FIG. 17 illustrates a method, shown generally at 1224, representative ofthe method of operation of an embodiment of the present disclosure. Themethod facilitates efficient utilization of radio resources in a radiocommunication system that provides for concurrent running of a firstpacket service and a second packet service. First, and as indicated bythe block 1226, detection is made of selection to release a radioresource associated with a selected packet service of the first packetservice and the second packet service. Then, and as indicated by theblock 1228, a radio resource release indication is sent responsive tothe detection of the selection to release the radio resource.

Then, at block 1212 the radio resource release indication is examinedand then at block 1214 the grant of the release of the radio bearer isselectably granted.

In a further embodiment, the network may initiate a transition based onboth the receipt of an indication from the user equipment or anothernetwork element and on a radio resource profile for the user equipment.

An indication as received from the user equipment or other networkelement could be any of the different transition indications describedabove. The indication can be passive and thus be merely a blankindication that a less battery intensive radio state should be entered.Alternatively the indication could be part of the regular indicationssent from the UE which the network determines, possibly over time or anumber of received indications, and the UE's radio resource profile thata less battery or radio resource intensive radio state should beentered. Alternatively, the indication could be dynamic and provideinformation to the network element about a preferred state or mode inwhich to transition. As with the above, the indication could contain acause for the indication (e.g. normal or abnormal). In a furtherembodiment, the indication could provide other information about a radioresource profile, such as a probability that the user equipment iscorrect about the ability to transition to a different state or mode, orinformation about the application(s) that triggered the indication.

An indication from another network element could include, for example,an indication from a media or push-to-talk network entity. In thisexample, the indication is sent to the network entity responsible fortransitioning (e.g. the UTRAN) when traffic conditions allow. Thissecond network entity could look at traffic at an Internet protocol (IP)level to determine whether and when to send a transition indication.

In a further embodiment, the indication from the UE or second networkelement could be implicit rather than explicit. For example, atransition indication may be implied by the network element responsiblefor transitioning (e.g., the UTRAN) from device status reports onoutbound traffic measurements. Specifically, status reporting couldinclude a radio link buffer status where, if no outbound data exists,could be interpreted as an implicit indication. Such status reportingcould be a measurement that can be repetitively sent from the UE thatdoes not, by itself, request or indicate anything.

The indication could thus be any signal and could be application based,radio resource based, or a composite indication providing informationconcerning all of the user equipment's application and radio resources.The above is not meant to be limiting to any particular indication, andone skilled in the art would appreciate that any indication could beused with the present method and disclosure.

Reference is now made to FIG. 18. The process starts at step 1801 andproceeds to step 1810 in which a network element receives theindication.

Once the network receives the indication in step 1810, the processproceeds to step 1820 in which a radio resource profile for the userequipment is optionally checked.

The term “radio resource profile”, as used herein, is meant to be abroad term that could apply to a variety of situations, depending on therequirements of a network element. In broad terms, the radio resourceprofile includes information about radio resources utilized by the userequipment.

The radio resource profile could include either or both static profileelements and dynamic or negotiated profile elements. Such elements couldinclude an “inhibit duration and/or maximum indication/request messagesper time-window” value, which could be part of the radio resourceprofile, either within or apart from the transition profile, and couldbe negotiated or static.

Static profile elements may include one or more of the quality ofservice for a radio resource (e.g., RAB or RB), a PDP context, an APNthat the network has knowledge of and a subscriber profile.

As will be appreciated by those skilled in the art, various levels ofquality service could exist for a radio resource and the level of thequality of service could provide information to a network on whether totransition to a different state or mode. Thus if the quality of serviceis background, the network element may consider transitioning to idlemore readily than if the quality of service is set to interactive.Further, if multiple radio resources have the same quality of service,this could provide an indication to the network on whether to transitionthe mobile device to a more suitable state or mode or to tear down theradio resources. In some embodiments, a primary and secondary PDPcontext could have a different quality of service, which could alsoaffect the decision on whether to perform a state/mode transition.

Further, the APN could provide the network with information about thetypical services that the PDP context utilizes. For example, if the APNis xyz.com, where xyz.com is typically used for the provision of dataservices such as email, this could provide an indication to the networkabout whether or not to transition to a different state or mode. Thiscould further indicate routing characteristics.

In particular, the present method and apparatus can utilize the AccessPoint Name (APN) specified by the UE to set the transition profilebetween various states. This may be another way of describing thesubscription of the UE. As will be appreciated, the Home LocationRegister (HLR) may store relevant information about subscribers, andcould provide the radio network controller (RNC) with the subscriptionof the UE. Other network entities could also be used to storesubscription information centrally. Whether using the HLR or othernetwork entity, information is preferably pushed to other networkcomponents such as the RNC and SGSN, which map subscription informationto relevant physical parameters used during data exchange.

The UTRAN could include or have access to a database or table in whichvarious APNs or QoS parameters could be linked to a specific transitionprofile. Thus, if the UE is an always-on device, this will be apparentfrom the APN and an appropriate transition profile for that APN could bestored at the UTRAN as part of the radio resource profile or be remotelyaccessible by the UTRAN. Similarly, if the QoS or a portion of the QoSparameter is used, or a dedicated message sent with a profile, thiscould signify to the UTRAN that a particular transition profile isdesired based on a database query or a lookup in a table. Additionally,a multiplicity of behaviors beyond the RRC connected state transitionprofile can be specified by this means. These include, but are notlimited to:

-   -   rate adaptation algorithms (periodicity of step/step size);    -   initial granted radio bearer;    -   maximal granted radio bearer;    -   minimize call setup time (avoid unnecessary steps such as        traffic volume measurements); and    -   the air interface (GPRS/EDGE/UMTS/HSDPA/HSUPA/LTE, etc.).

Further, if there are multiple PDP contexts that have different QoSrequirement but share the same APN IP address, such as a primarycontext, secondary context, and so forth, a different transition profilecan be used for each context. This could be signaled to the UTRANthrough QoS or dedicated messages.

If multiple active PDP contexts are concurrently utilized, the lowestcommon denominator between the contexts can be used. For RRC statetransition, if one application has a first PDP context that isassociated with a transition profile in which the system moves fromCELL_DCH state to a CELL_PCH or Idle state quickly, and a second PDPcontext is associated with a transition profile in which the system isto stay in the CELL_DCH state longer, the second profile in which theCELL_DCH state is maintained longer will override the first profile.

As will be appreciated by those skilled in the art, the lowest commondenominator can be considered in two different ways. Lowest commondenominator, as used herein, implies a longest time required beforetransitioning to a different state. In a first embodiment, the lowestcommon denominator may be the lowest of the activated PDPs. In analternative embodiment, the lowest common denominator may be the lowestof the PDPs that actually have active radio resources. The radioresources could be multiplexed in a number of different fashions but theend result is the same.

An exemplary case for such methods can be drawn for always on devices.As described, various APNs or QoS parameters can be linked to a specificbehavior for always on. Consider initially granted radio resources thatmay be desirable based on an ‘always on’ profile. The network now has ameans to ‘know’ that data bursts are short and bursty for always-onapplications, such as email. For those skilled in the art, it is clearlyseen that given this information, there is no incentive to save codespace for trunking efficiency on the network. Thus a maximum rate may beallocated to an always-on device with little risk of not reservingenough code space for other users. Additionally the UE benefits inreceiving data more rapidly and also saves on battery life due toshorter ‘on time’. Again, to those skilled in the art, high data rateshave very little effect on current draw since power amplifiers are fullybiased regardless of data rate.

In the above embodiment, a lookup table can be used by the UTRAN todetermine the resource control profile for radio resources(s) to beassigned for different applications for a given RRC connection for theUE. The profile can be based on user subscription and stored on thenetwork side at a network entity such as HLR or alternatively at the RNCsince the RNC will have more up to date traffic resources available(i.e., data rates that can be granted). If higher data rates can beachieved, shorter timeouts may be possible.

Instead of APN, other alternatives such the Quality of Service (QoS)parameters set in a Packet Data Protocol (PDP) Context activation orModified PDP Context can be used. The QoS field can further include theQoS “allocation retention priority (Service data unit could be used toinfer traffic data volumes)” in case of multiple PDP contexts sharingthe same APN address or a subscription profile to set the transitionprofile. Further alternatives include dedicated messages such as theindication message above to signal a resource control profile andinformation such as inhibit duration and/or maximum indication/requestmessages per time-window value.

The transition profile included in the radio resource profile couldfurther include whether the state of the UE should be transition at allbased on the type of application. Specifically, if the user equipment isbeing used as a data modem, a preference may be set either on the userequipment so transition indications are not sent or if knowledge of thepreference is maintained at the network, that any transition indicationreceived from the UE while being used as a data modem should be ignored.Thus the nature of the applications that are being run on the userequipment could be used as part of the radio resource profile.

A further parameter of a transition profile could involve the type oftransition. Specifically, in a UMTS network, the user equipment mayprefer to enter a Cell_PCH state rather than entering an idle state forvarious reasons. One reason could be that the UE needs to connect to aCell_DCH state more quickly if data needs to be sent or received, andthus moving to a Cell_PCH state will save some network signaling andbattery resources while still providing for a quick transition to theCell_DCH state. The above is equally applicable in non-UMTS networks andmay provide for a transition profile between various connected and idlestates.

The transition profile may also include various timers including, butnot limited to, inhibit duration and/or maximum indication/requestmessages per time-window, delay timers and inactivity timers. Delaytimers provide a period which the network element will wait prior totransitioning to a new state or mode. As will be appreciated, even ifthe application has been inactive for a particular time period, a delaymay be beneficial in order to ensure that no further data is received ortransmitted from the application. An inactivity timer could measure apredetermined time period in which no data is received or sent by anapplication. If data is received prior to the inactivity timer expiring,typically the inactivity timer will be reset. Once the inactivity timerexpires, the user equipment may then send the indication of step 1810 tothe network. Alternatively, the user equipment may wait for a certainperiod, such as that defined for the delay timer, before sending theindication of step 1810.

Further, the delay timer or inhibit duration and/or maximumindication/request messages per time-window could vary based on aprofile that is provided to the network element. Thus, if theapplication that has requested a transition to a different mode or stateis a first type of application, such as an email application, the delaytimer on the network element can be set to a first delay time, while ifthe application is of a second type such as an instant messagingapplication, the delay timer can be set to a second value. The values ofthe inhibit duration and/or maximum indication/request messages pertime-window, delay timer or inactivity timer could also be derived bythe network based on the APN utilized for a particular PDP.

As will be appreciated by those skilled in the art, the inactivity timercould similarly vary based on the application utilized. Thus, an emailapplication may have a shorter inactivity timer than a browserapplication since the email application is expecting a discrete messageafter which it may not receive data. Conversely the browser applicationmay utilize data even after a longer delay and thus require a longerinactivity timer.

The transition profile may further include a probability that a userequipment is correct requesting a transition. This could be based oncompiled statistics on the rate of accuracy of a particular userequipment or application on the user equipment.

The transition profile may further include various discontinuousreception (DRX) time values. Further, a progression profile for DRXtimes could be provided in a transition profile.

The transition profile could be defined on an application by applicationbasis or be a composite of the various applications on the userequipment.

As will be appreciated by those skilled in the art the transitionprofile could be created or modified dynamically when a radio resourceis allocated and could be done on subscription, PS registration, PDPactivation, RAB or RB activation or changed on the fly for the PDP orRAB/RB. The transition profile could also be part of the indication ofstep 1810. In this case, the network may consider the preferred RRCstate indication to determine whether to allow the transition and towhat state/mode. Modification could occur based on available networkresources, traffic patterns, among others.

The radio resource profile is therefore comprised of static and/ordynamic fields. The radio resource profile used by a particular networkmay vary from other networks and the description above is not meant tolimit the present method and system. In particular, the radio resourcesprofile could include and exclude various elements described above. Forexample, in some cases the radio resource profile will merely includethe quality of service for a particular radio resource and include noother information. In other cases, the radio resource profile willinclude only the transition profile. Still in other cases, the radioresource profile will include all of the quality of service, APN, PDPcontext, transition profile, among others.

Optionally, in addition to a radio resource profile, the network elementcould also utilize safeguards to avoid unnecessary transitions. Suchsafeguards could include, but are not limited to, the number ofindications received in a predetermined time period, the total number ofindications received, traffic patterns and historical data.

The number of indications received in a predetermined time period couldindicate to the network that a transition should not occur. Thus, if theuser equipment has sent, for example, five indications within a thirtysecond time period, the network may consider that it should ignore theindications and not perform any transitions. Alternatively the networkmay determine to indicate to the UE that it should not send any furtherindications either indefinitely or for some configured or predefinedtime period. This could be independent of any “inhibit duration and/ormaximum indication/request messages per time-window” on the UE.

Further, the UE could be configured not to send further indications fora configured, predefined or negotiated time period. The UE configurationcould be exclusive of the safeguards on the network side describedabove.

The traffic patterns and historical data could provide an indication tothe network that a transition should not occur. For example, if the userhas received a significant amount of data in the past between 8:30 and8:35 a.m. from Monday to Friday, if the indication is received at 8:32a.m. on Thursday, the network may decide that it should not transitionthe user equipment since more data is likely before 8:35 a.m.

If multiple radio resources are allocated for the user equipment, thenetwork may need to consider the complete radio resource profile for theuser equipment. In this case, the radio resource profiles for each radioresource can be examined and a composite transition decision made. Basedon the radio resource profile of one or multiple radio resources, thenetwork can then decide whether or not a transition should be made.

A Further Limitation on Transition Indications

As described previously, there are various mechanisms by which a UE mayhave transitioned to its current RRC state. The initiation for thetransition may have been entirely driven by the network, for example asa result of observed inactivity. In this example, the network maintainsinactivity timers for each of the RRC states. If the inactivity timerfor the current RRC state of the UE expires, then the network will sendan RRC reconfiguration message to transition the UE to a differentstate. Alternatively, the initiation of the transition may have beendriven by the UE using a transition indication mechanism as describedabove (e.g., with use of a transition indication message). Since thenetwork has control of the RRC state machine, in this case the UE cansend an indication to the network that it does not need to be kept inthe current RRC state and is requesting a transition to a less batteryconsumptive RRC state.

In one embodiment, a limitation is placed on the UE's ability totransmit a transition indication that is a function of whether or notthe UE underwent the most recent transition to its current state as aresult of a transition indication previously transmitted by the UE.

In another embodiment, the number of transition indications that the UEmay send in its current state is a function of whether or not the UEunderwent the most recent transition to its current state as a result ofa transition indication previously transmitted by the UE.

In another embodiment, the number of transition indications that the UEmay send in specific states is limited regardless of the manner in whichthe UE underwent the most recent transition to its current state wherethe current state is one of the specific states that this limitationapplies to.

Inhibit any Further Transition Indication Following a RRC State Changefrom a Previously Transmitted Transmission Indication

In some embodiments, if the UE is in its current state as a result ofhaving previously transmitted a transition indication, the UE isinhibited from transmitting any further transition indications while inthis current state.

The UE may maintain a flag, bit token, or other indicator whichindicates whether the UE is permitted to send transition indications tothe network while it remains in its current state. If the UE isreconfigured by the network to a new RRC state (e.g., the network sendsa reconfiguration message to the UE to effect a transition to the newRRC state) after having sent a transition indication to the network,then this flag, bit token, or other indicator is set (or alternatelycleared), indicating the UE is not permitted to send further transitionindications while it remains in this current state. If the UE changesRRC state due to a data transaction request by the UE (e.g. because itsbuffer shows that it has data to be sent) or by the network (e.g.because the network has paged the UE), then this indicator is cleared(or alternatively set) to indicate that the UE is once again permittedto send a transition indication to the network.

Inhibit More than a Predetermined Number of Transition IndicationsFollowing a RRC State Change From a Previously Transmitted TransitionIndication

In some embodiments, if the UE is in its current state as a result ofhaving previously transmitted a transition indication, the UE isinhibited from transmitting any more than a predetermined maximum numberof further transition indications while the network maintains the UE inthis same current state. In some embodiments, the predetermined numberis hard coded in the UE. In other embodiments, the predetermined numberis configured by the network, and is subject to be changed as the UEmoves between different networks. The network configuration may takeplace, for example, using a signalling message directly to the mobilestation, or as part of a broadcast message.

The UE maintains a flag, bit token, or other indicator which indicateswhether the UE is permitted to send a fixed number of transitionindications to the network while it remains in its current state. If theUE has transitioned to this current state as a result of having sent atransition indication in a previous state, then this flag, bit token, orother indicator will be set. If the UE has transitioned to this currentstate as a result of normal network driven transitions based oninactivity timers for example, then this flag, bit token, or otherindicator will not be set and there will be no restrictions on thenumber of transition indications that the UE may send in its currentstate.

In the case where the flag, bit token, or indicator is set indicatingthat the UE is only permitted to send a fixed number of transitionindicators to the network while it remains in this current state, the UEmay, in addition maintain a counter which counts the number oftransition indications that are sent by the UE after it has determinedthat it has just been transitioned to its current state as a result of apreviously transmitted transition indication.

In this example, if once in the current state, the UE subsequently wantsto transmit a transition indication from this current state, it firstlooks at the flag, bit token or other indicator to see if it limited inthe number of transition indications it may send to the network while itremains in its current state. If it is limited, then the UE keeps countof the number of transition indications it sends provided the networkresponse to the transition indicator is to move the UE to its currentRRC state (in the case where the UE needs to transition to another RRCstate to send the transition indication message) or to leave the UE inits current state (in the case where the UE may send the transitionindicator in its current state).

If when the UE compares the value of its transition indication counterto the predetermined maximum number of further transition indicationspermitted (possibly indicated by a flag, bit token or other indicator),the value of the transition indication counter is greater than thispredetermined maximum number, then the UE will not subsequently sendfurther transition indications to the network.

If the result of a transition indication sent by the UE is that the UEis transitioned to a different RRC state from its current state (by forexample a reconfiguration message sent by the network) prior to sendingthe transition indication, that is more battery intensive than thecurrent state, then the counter is reset and the process begins again inthe new current state. This would be the case, for example, if the endresult is that the UE is reconfigured from a PCH to CELL_FACH.

If the UE changes RRC state due to a data transaction request by the UE(e.g. because its buffer shows that it has data to be sent) or by thenetwork (e.g. because the network has paged the UE), then this indicatoris cleared (or alternatively set) to indicate that the UE is once againpermitted to send a transition indication to the network and the counteris reset.

Inhibit More than a Predetermined Number of Transition Indications

In some embodiments, the UE is inhibited from transmitting any more thana predetermined maximum number transition indications while the networkmaintains the UE in its same current state. In some embodiments, thepredetermined number is hard coded on the UE. In other embodiments, thepredetermined number is configured by the network, and is subject to bechanged as the mobile station moves between different networks. Thenetwork configuration may take place, for example, using a signallingmessage directly to the mobile station, or as part of a broadcastmessage.

The UE maintains a counter which counts the number of transitionindications that are sent by the UE after from its current state.Therefore upon transitioning to the current state, and the UEsubsequently wants to transmit a transition indication from this currentstate, then the UE keeps count of the number of transition indicationsit sends provided the network response to the transition indicator is toreturn the UE to its current RRC state (in the case where the UE needsto transition to another RRC state to send the transition indicationmessage) or to leave the UE in its current state (in the case where theUE may send the transition indicator in its current state).

If when the UE compares the value of its transition indication counterto the predetermined maximum number of further transition indications,the value of the transition indication counter is greater than thispredetermined maximum number, then the UE will not subsequently sendfurther transition indications to the network.

If the result of a transition indication sent by the UE is that the UEis reconfigured to a different RRC state from its current state prior tosending the transition indication, and the different RRC state is morebattery intensive than the current state, then the counter is reset andthe process begins again in the new current state.

If the UE changes RRC state due to a data transaction request by the UE(e.g. because its buffer shows that it has data to be sent) or by thenetwork (e.g. because the network has paged the UE), then this indicatoris cleared (or alternatively set) to indicate that the UE is once againpermitted to send a transition indication to the network and the counteris reset.

Whether or not there is a state transition that resulted from havingpreviously transmitted, a transition indication can be used toenable/disable or limit the further transmission of transitionindications in various ways:

1) a prerequisite to allowing the transmission of a transitionindication is that the previous state transition must not have been theresult of the UE having previously transmitted a transition indication.This prerequisite can be combined with other prerequisites orinhibitions such that satisfaction of the prerequisite alone may notnecessarily allow the UE to transmit a transition indication

2) a prerequisite to allowing the transmission of a transitionindication is that if the previous state transition was the result ofthe UE having previously transmitted a transition indication, no morethan a defined number of transition indications have been transmitted bythe UE. This prerequisite can be combined with other prerequisites orinhibitions such that satisfaction of the prerequisite alone may notnecessarily allow the UE to transmit a transition indication

3) if the previous state transition was the result of the UE havingpreviously transmitted a transition indication, inhibit transmission ofa transition indication. This is logically equivalent to 1) above. Thisinhibition can be combined with other prerequisites or inhibitions suchif the inhibition is not triggered, that alone may not necessarily allowthe UE to transmit a transition indication.

4) if the previous state transition was the result of the UE havingpreviously transmitted a transition indication, inhibit transmission ofany more than a defined number of transition indications. This islogically equivalent to 2) above. This inhibition can be combined withother prerequisites or inhibitions such if the inhibition is nottriggered, that alone may not necessarily allow the UE to transmit atransition indication.

5) if the previous state transition was not UE driven, allowtransmission of a transition indication.

6) if the previous state transition was the result of the UE havingpreviously transmitted a transition indication, allow transmission ofonly up to a defined number of transition indications.

7) for certain RRC states, allow transmission of only up to a definednumber of transition indications.

Interplay with Inhibit Timer

As indicated above, the state transition-based prerequisite orinhibition can be combined with other prerequisites or inhibitions.Embodiments have been described above which inhibit a UE from sending atransition indication for some period of time after previously sending atransition indication. In some embodiments, this inhibition is combinedwith the state transition-based inhibition/prerequisite described above.

For example, the use of an inhibit timer has been described previouslyas one mechanism for inhibiting the UE from sending a transitionindication for some period of time after previously sending a transitionindication, in which an inhibit timer is started after transmitting atransition indication, and the UE is allowed to send a furthertransition indication only if the inhibit timer is not running. In someembodiments the use of this inhibit timer is combined with the statetransition-based inhibition as follows:

previous state transition the result of the UE having previouslytransmitted a transition indication? inhibit transmission of transitionindication, or inhibit the transmission of more than a defined number oftransition indications subsequent to a previous transition that was theresult of the UE having previously transmitted a transition indication;and

is inhibit timer running? inhibit transmission of transition indication.

In some embodiments, these are the only two inhibitions in place inwhich case, the behaviour can be summarized as follows:

allow transmission of a transition indication if the inhibit timer isnot running, and the current state was not a result of a previoustransition indication transmitted by the UE, or

allow transmission of a transition indication if the inhibit timer isnot running, and if fewer than a defined number of transitionindications have been transmitted subsequent to a state transition thatwas the result of the UE having previously transmitted a transitionindication.

Previous State Transition Cause Maintenance

The UE has a mechanism for maintaining an indication of whether thecurrent state is a result of the previous transmission of a transitionindication by the UE. This indication can be a previous state transitioncause value stored in a memory on the UE that is accessible by aprocessor forming part of the UE, or a switch implemented in hardware toname a few examples. In a specific example, the previous statetransition cause is a single bit that is a first value (‘1’ or ‘0’) toindicate that the previous state transition the result of the UE havingpreviously transmitted a transition indication, and is otherwise asecond value (‘0’ or ‘1’).

Previous State Transition Cause Assessment

The UE has a mechanism for determining whether the current state is aresult of the previous transmission of a transition indication by theUE.

If the UE has sent the transition indication, and this has beenacknowledged by the network so the UE knows that the network receivedit, then the UE may know that if it receives an RRC reconfigurationmessage within a fixed period of time, that this RRC configurationmessage is a result of the sending of the transition indication.

If the UE receives an RRC reconfiguration and it has not sent (and hadacknowledged) a transition indication within a predetermined period oftime leading up to the reconfiguration, then the UE can assume that thestate transition was not in response to the transmission of a transitionindication by the UE.

In a first example, each time a state transition occurs as a result of areconfiguration by the network, the UE assesses whether the statetransition was the result of the UE having previously transmitted atransition indication. If this was the case, the UE updates the previousstate transition cause to indicate that the previous state transitionwas UE driven. If the state transition was other than the result of theUE having previously transmitted a transition indication, then theprevious state transition cause is updated accordingly.

In some embodiments, where a transition with cause value is supported,the UE determines whether it had previously sent a transition indicationwith a cause value for which this mechanism is to be implemented priorto receiving this reconfiguration.

In some embodiments the UE performs the following steps to determinewhether a state transition is the result of the UE having previouslytransmitted a transition indication:

1) transmit a transition indication (or transition indication withparticular cause value);

2) if a state transition that is consistent with the transitionindication occurs within a defined time interval of transmitting thetransition indication, assess the state transition to be the result ofthe UE having previously transmitted a transition indication, andotherwise assess the state transition to be other than the result of theUE having previously transmitted a transition indication.

In some embodiments, upon transmitting a transition indication, a timeris started that counts down starting at a timeout value, or equivalentlythat counts up to a timeout value. If the timer is still running whenthe state transition occurs, then it is assessed as being the result ofthe UE having previously transmitted a transition indication.

In some embodiments, any of these embodiments are implemented using atransition indication that includes a cause code to allow the UE tospecify a cause for the transition indication (e.g., to indicate that adata transfer or call is complete, or that no further data is expectedfor a prolonged period). A specific example is the SIGNALLING CONNECTIONRELEASE INDICATION defined in 3GPP TS 25.331 Section 8.1.14 where thecause code is the IE “Signalling Connection Release Indication Cause”set to “UE Requested PS Data session end”.

In some embodiments, any of these embodiments are implemented using atransition indication that does not include a cause code. A specificexample is the SIGNALLING CONNECTION RELEASE INDICATION defined in 3GPPTS 25.331 Section 8.1.14.

Further Example of Determination of the Mechanism for the RRC StateTransition

If the UE receives an RRC reconfiguration message from the network, itcan determine if it has sent a SCRI message with the cause value “UERequested PS Data session end” prior to receiving this reconfiguration.

If the UE has sent this message, and the message has been acknowledgedby the network so the UE knows that the network received it, then the UEmay know that if it receives and RRC reconfiguration message within afixed period of time, that this RRC configuration message is a result ofthe sending of the SCRI.

If the UE is in CELL_DCH or CELL_FACH RRC state and it has sent a SCRIwhich has been acknowledged but the network does not send an RRCreconfiguration within a fixed period of time, then the UE can assumethat it is currently in the state that the network wants it to remainin, and the UE can consider that the mechanism for which it remains inthat state is for Fast Dormancy purposes.

If the UE receives an RRC reconfiguration and it has not sent (and hadacknowledged) a SCRI message the fixed period of time leading up to thereconfiguration, then the UE can assume that the state transition wasnot for Fast Dormancy purposes.

SPECIFIC EXAMPLES

With reference to the state diagram of FIG. 1, assume that a UE isinitially in the Cell_DCH state 122. After that, the UE transmits atransition indication, for example upon determining it has no more datato send. In response, the network acknowledges the transition indicationand transitions the UE to URA_PCH. In some embodiments, this is a directstate transition. In other embodiments, this is an indirect statetransition via the cell_FACH state. After that, the UE is not allowed tosend another transition indication.

Note that in general, the description of embodiments and behaviour thatpertain to the URA_PCH state also apply to the CELL_PCH state.

If, on the other hand, the network decides on its own to transition theUE to URA_PCH, for example due to expiry of an inactivity timer, the UEis allowed to send a transition indication. At this point, the UE islooking to transition to IDLE mode from URA_PCH. However, the UE musttransition to CELL_FACH to send the transition indication. Recall thatthe purpose of the transition indication is for the UE to move to a lessbattery-intensive state. If the network leaves the UE in CELL_FACH, thisis not a transition to a more battery efficient state (the only morebattery efficient state from URA_PCH being IDLE) and so the CELL_FACHstate is not considered to be as the result of a previous transmissionof a transition indication. If the network transitions the UE to URA_PCHor IDLE mode within a defined period, then the state transition isconsidered to be as a result of a previous transmission of a transitionindication.

Another Inhibition

In some embodiments, if the UE has sent a transition indication whichhas been acknowledged but the network does not send an RRCreconfiguration within a fixed period of time, then the UE assumes thatit is currently in the state that the network wants it to remain in. Insome embodiments, upon this sequence of events taking place, the UE isinhibited from transmitting a transition indication, even though thecurrent state may not necessarily be the result of the UE havingpreviously transmitted a transition indication.

In some embodiments, the above-described inhibition is only implementedif the state that the UE remains in is the CELL_DCH or CELL_FACH RRCstate.

State Due to (Fast Dormancy

In some embodiments, when the UE is in a state that is a result of apreviously transmitted transition indication, the UE is said to be in astate due to invoking fast dormancy. In some embodiments, when the UEhas transmitted a transition indication which is acknowledged, but theUE does not undergo a state change, the UE is also said to be in a statedue to invoking fast dormancy.

If the UE is transitioned to an RRC state (that is not IDLE) and thiswas not because of a transition indication (also referred to as atransition indication for fast dormancy purposes), then the UE uses theinhibit timer in order to determine when it is allowed to send atransition indicator for fast dormancy purposes. This behaviour iscurrently described in 3GPP TS 25.331.

If the UE is transitioned to an RRC state (that is not IDLE) and thiswas due to a transition indication, then the UE will have differentconstraints on its behaviour. The UE will set some sort of flag orindication internally when it knows that it is in this situation. Thismay, for example, be referred to as the FDM (Fast Dormancy Mechanism)flag.

In one case, the UE may be inhibited from sending a further transitionindication. Alternatively, the UE may be allowed to send furtherrequests for a state transition, but the number of further requests islimited to some defined number, for example one or more. The periodbetween sending these requests is controlled by the inhibit timer.

If when the UE requests a state transition using the transitionindication (and this has been acknowledged) the network either leavesthe UE in its current RRC state (e.g. for CELL_FACH) or moves it back tothe RRC state from which it sent the transition indicator from (e.g. theUE was in CELL_PCH, moved to CELL_FACH to send the SCRI, then thenetwork moved the UE back to CELL_PCH) then the UE decrements the numberof remaining transition indication requests that it is allowed to send.

If the UE moves to a different RRC state because a data transaction isinitiated (e.g. it receives a page and is responding to this, or itrequests resources for a data transaction) then the UE clears the FDMflag and the procedure restarts.

If the UE makes a transition to CELL_FACH state to transmit aCELL_UPDATE message or a URA_UPDATE message and in the acknowledgementfrom the network the UE is moved back to CELL_PCH or URA_PCH state, thenthis does not clear the FDM flag.

If however the UE makes a transition to CELL_FACH state to transmit aCELL_UPDATE message or a URA_UPDATE message or a transition indicationmessage, and the network subsequently leaves the UE in CELL_FACH state,then the UE does clear the FDM flag and the procedure restarts.

In some cases, the UE is prevented entirely from sending the SCRImessage after the UE is transitioned to a different RRC state inresponse to a Fast Dormancy request using the SCRI message with thecause value “UE Requested PS Data session end”. In this case the UE setsthe FDM flag and only clears this flag when it moves to a different RRCstate for a data transaction that is initiated by the UE or by thenetwork.

In some cases, the UE is only allowed a predefined maximum number oftransition indication messages in certain predefined states. The numbercan be different for different states. For instance the UE may only beallowed to transmit “n” transition indication messages (with or withoutthe cause code as described above) when in CELL_PCH or URA_PCH RRCStates.

In some embodiments, methods and devices that are compliant with 3GPP TS25.331 Universal Mobile Telecommunications System (UMTS); Radio ResourceControl (RRC); Protocol specification, Release 8, or an evolutionthereof, with amendments to facilitate or implement one or more of theembodiments described herein are provided. Examples of this are providedin Appendix A, Appendix B, and Appendix C. All of these examples referto the use of the SCRI, but more generally the use of any transitionindication is contemplated.

In some embodiments (see Appendix A for an example implementation), a UEinternal state variable is defined which is set the first time the UEtriggered FD from within PCH state. If set the UE is then prevented fromtriggering FD again from within PCH state, the variable is reset whennew PS data arrives for transmission.

In some embodiments (see Appendix B for an example implementation), acounter V316 is defined and initially set to zero. The UE in PCH stateis permitted to trigger sending a transition indication (such as a SCRI)with cause if V316<N316 (N316 is the max value). If UE does triggersending of a transition indication (such as a SCRI with cause value) inPCH state then V316 is incremented. V316 is reset to zero if the UE ispaged in PCH state or if the UE has uplink PS data available fortransition.

If N316 is fixed to be 1 then the behaviour is equivalent to V316 beinga Boolean state variable. Note that the UE having PS data available fortransmission specifically excludes the sending of a transitionindication (such as SCRI with cause) and causes the counter V316 to bereset. In this context, the PS having data available may, for example,mean that the user has data to transmit on RB3 (radio bearer 3) orupwards (the SCRI message is sent on RB2).

Note the text proposal in 8.3.1.2 (cell update procedure) and the finalparagraph of 8.1.14.2 are alternative ways of capturing the conditionfor resetting V316.

In some embodiments (see appendix C for an example implementation), theUE is inhibited from transmitting a transition indication (such as aSCRI with cause) if the network moves the UE to PCH state in response toa transition indication (such as SCRI with cause) transmitted by the UEwhile in DCH or FACH state. To inhibit the transition indication (suchas SCRI with cause) may be done by setting V316 to N316. The UE assesswhether the move is instructed by the network ‘in response’ to thetransition indication. Mechanisms described previously can be used forthis; for example, the UE may judge this to be the case if thereconfiguration is received within a certain time of sending thetransition indication.

In some embodiments, a new flag may be added to the reconfigurationmessage which can be set to TRUE if the reconfiguration message istriggered in the network by the receipt of a SCRI with cause, thusenabling the UE to know for certain is the reconfiguration is inresponse to the SCRI with cause. An example of this is depicted inAppendix D.

Many different embodiments for inhibiting the transmission of atransition indication, either completely, or to some maximum number oftransition indications, have been described. Many of these are afunction of one or more of:

whether the current state of the UE is the result of a previous statetransition;

whether the current state is the same as the UE's state prior to sendinga state transition, whether the current state is more battery intensivethan the UE's state prior to sending a state transition.

In some embodiments, a mechanism for inhibiting the transmission of atransition indication is implemented, or not, on a per state basis; insome embodiments, for certain states no mechanism is implemented. Inother embodiments, a different mechanism is used for each of at leasttwo states.

In one embodiment, the network has a plurality of choices on how toproceed when it has received and indication in step 1810 and optionallyexamined the radio resource profile or profiles in step 1820.

A first option is to do nothing. The network may decide that atransition is not warranted and thus not accept the user equipmentindication to transition. As will be appreciated by those skilled in theart, doing nothing saves network signaling since the state is notchanged and in particular since a transition is not triggered.

A second option is to change the state of the device. For example, in aUMTS network, the state of the device may change from Cell_DCH toCell_PCH. In non-UMTS networks the state transition may occur betweenconnected states. As will be appreciated by those skilled in the art,changing states reduces the amount of core network signaling whencompared with a transition to idle mode. Changing the state can alsosave radio resources since the Cell_PCH state does not require adedicated channel. Also Cell_PCH is less battery intensive stateenabling the UE to preserve battery power.

A third option for the network is to keep the UE in the same state butrelease the radio resources associated with a particular APN or PDPcontext. This approach saves radio resources and signaling as theconnection is maintained in its current state and does not need to bere-established. However, it may be less suitable for situations where UEbattery life is a concern.

A fourth option for the network is to transition the UE to an Idle mode.In particular, in both UMTS and non-UMTS, the network may move from aconnected mode to an Idle mode. As will be appreciated, this saves radioresources since no connection at all is maintained. It further saves thebattery life on the user equipment. However, a greater amount of corenetwork signaling is required to reestablish the connection.

A fifth option for the network is to change a data rate allocation,which will save radio resources, typically allowing more users to usethe network.

Other options would be evident to those skilled in the art.

The decision of the network on which of the five or more options toutilize will vary from network to network. Some overloaded networks mayprefer to preserve radio resources and thus would choose the third,fourth or fifth options above. Other networks prefer to minimizesignaling and thus may choose the first or second options above.

The decision is shown in FIG. 18 at step 1830 and may be based onnetwork preferences along with the radio resource profile for the userequipment. The decision is triggered by the network receiving anindication from the user equipment that the user equipment would like totransition into another state e.g. into a less battery intensive state.

Reference is now made to FIG. 19. FIG. 19 illustrates the simplifiednetwork element adapted to make the decisions shown in FIG. 18 above.Network element 1910 includes a communications subsystem 1920 adapted tocommunicate with user equipment. As will be appreciated by those skilledin the art communications subsystem 1920 does not need to directlycommunicate with user equipment, but could be part of a communicationspath for communications to and from the user equipment.

Network element 1910 further includes a processor 1930 and a storage1940. Storage 1940 is adapted to store preconfigured or static radioresource profiles for each user equipment being serviced by networkelement 1910. Processor 1930 is adapted to, upon receipt of anindication by communications subsystem 1920, consider the radio resourceprofile for the user equipment and to decide on a network actionregarding transitioning the user equipment. As will be appreciated bythose skilled in the art, the indication received by communicationssubsystem 1920 could further include a portion of or all of the radioresource profile for the user equipment that would then be utilized byprocessor 1930 to make the network decision concerning any transition.

Based on the above, a network element therefore receives an indicationfrom the user equipment that a transition might be in order (such as forexample when a data exchange is complete and/or that no further data isexpected at the UE). Based on this indication, the network elementoptionally checks the radio resource profile of the user equipment,which could include both static and dynamic profile elements. Thenetwork element may further check safeguards to ensure that unnecessarytransitions are not occurring. The network element could then decide todo nothing or to transition to a different mode or state, or to teardown a radio resource. As will be appreciated, this provides the networkmore control of its radio resources and allows the network to configuretransition decisions based on network preferences rather than merelyuser equipment preferences. Further, in some cases the network has moreinformation than the device concerning whether to transition. Forexample, the user equipment has knowledge of upstream communications andbased on this may decide that the connection may be torn down. However,the network may have received downstream communications for the userequipment and thus realized that it cannot tear down the connection. Inthis case, a delay can also be introduced using the delay timer toprovide the network with more certainty that no data will be receivedfor user equipment in the near future.

The embodiments described herein are examples of structures, systems ormethods having elements corresponding to elements of the techniques ofthis disclosure. This written description may enable those skilled inthe art to make and use embodiments having alternative elements thatlikewise correspond to the elements of the techniques of thisdisclosure. The intended scope of the techniques of this disclosure thusincludes other structures, systems or methods that do not differ fromthe techniques of this disclosure as described herein, and furtherincludes other structures, systems or methods with insubstantialdifferences from the techniques of this disclosure as described herein.

The invention claimed is:
 1. A method comprising: maintaining, at a userequipment (UE), a count of signaling connection release indication(SCRI) messages sent by the UE to a network, said count maintained whilea SCRI inhibit timer is not running; determining whether a current valueof the count is equal to or exceeds a predetermined value; responsive toa determination of the current value of the count being equal to orexceeding the predetermined value, stopping the sending of further SCRImessages with a cause set; while the sending of further SCRI messageswith a cause set is stopped, determining that the UE has uplink packetswitched (PS) data to transmit or the UE has received a page; and inresponse to determining the UE having uplink PS data to transmit orreceiving a page, resetting the count at the UE before sending furtherSCRI messages.
 2. The method of claim 1, wherein the SCRI messages sentby the UE each have a cause set.
 3. The method of claim 2, wherein thecause is set to UE Requested PS Data session end.
 4. The method of claim1, wherein the SCRI messages are sent by the UE while in at least oneradio resource control (RRC) state.
 5. The method of claim 4, whereinthe at least one RRC state comprises a CELL_PCH state or a URA_PCHstate.
 6. The method of claim 1, wherein maintaining a count comprisesusing a counter.
 7. The method of claim 1, wherein said maintainingincludes incrementing the count.
 8. A user equipment (UE) comprising aprocessor, configured to: maintain a count of signaling connectionrelease indication (SCRI) messages sent by the UE to a network saidcount maintained while a SCRI inhibit timer is not running; determinewhether a current value of the count is equal to or exceeds apredetermined value; responsive to a determination of the current valueof the count being equal to or exceeding the predetermined value, stopthe sending of further SCRI messages with a cause set; while the sendingof further SCRI messages with a cause set is stopped, determine that theUE has uplink packet switched (PS) data to transmit or the UE hasreceived a page; and in response to determining the UE having uplink PSdata to transmit or receiving a page, reset the count at the UE beforesending further SCRI messages.
 9. The UE of claim 8, wherein theindication messages sent by the UE each have a cause set.
 10. The UE ofclaim 8, wherein the cause is set to UE Requested PS Data session end.11. The UE of claim 8, wherein the indication messages are sent by theUE while in at least one radio resource control (RRC) state.
 12. The UEof claim 11, wherein the at least one RRC state comprises a CELL_PCHstate or a URA_PCH state.
 13. The UE of claim 8, wherein maintaining acount comprises using a counter.
 14. The UE of claim 8, wherein saidmaintaining includes incrementing the count.